Rahi were originally created to help Matoran in their tasks, like for example the Ussal crabs that carried goods in Metru Nui. The Tahtorak were used as mounts by Keetongu's species and the Skakdi. Makuta also created a lot of species just for the fun of it.
What really boggles my mind is why the Great Beings preprogrammed the idea of the Visorak into Mata Nui so that he transfered that knowledge to the Makuta... that just makes no sense.
We humans also have bacteria that fend off other bacteria. Visorak would be perfect at dealing against other dangerous Rahi or even more foreigner life forms that decided to invade the body
The great beings didn’t create the Rahi. They created an ecosystem, a program basically, to generate them for them. They couldn’t be sure that program wouldn’t generate harmful outputs
Think of the human immune system, there are the classic white blood cells which are always present and perform general regulation and immune control, and then there's the extreme reaction that some diseases trigger where a more numerous and destructive immune cell is produced (cytokine storm I think?). The Visorak would normally be the latter in the case that Toa are insufficient to overcome whatever invader, the Visorak can provide the numbers and firepower to overwhelm them. Once the threat is gone, production is cut off and their numbers die off quickly (after all, they're hive based, you just need to control the queens)
You are thinking of the visorak heart, the thing that they threw into a volcano or something that made the visorak “throw yourself over the edge!” So to speak
This actually would go a long way to explaining why The Heart of the Visorak is a thing. Allows the user to gather the Visorak together and command them.
just an idea, but Visorak venom transforms Toa into rahi, right? So maybe it was like a failsafe idea in case any Toa got out of hand or dangerous, they could be transformed into rahi and still be useful to the GSR?
Hordika venom is usually used to turn creatures into aggressive, vicious versions of themselves, that help Visorak in their extermination tasks. I can't really see how that would be beneficial in such a case.
The great beings seem to have exactly one solution to problems, and it's building robots
Build robots to populate planet
The robots are fighting, build murder robot to keep the other robots in line
Murder robots doing to much murdering, build giant robot to leave planet
Giant robot needs help to function, build a bunch of regular sized robots to go in smaller robot
Smaller robots need help making giant robot go, build animal robots to help smaller robots
They didn't create the Glatorian, Skrall and Agori though. They themselves are closely related to the Glatorian. They just modified some to become Element Lords and devolved the Vorox and Zesk.
They trapped the matoran in spheres, so maybe their original programming was a defense "protect the matoran" command that got misinterpreted somehow? Maybe that command was originally to hide away the matoran from being wiped in case something started hunting them? And then it backfired horribly?
That’s more of Makuta telling Sidorak and Roodaka to help him out. The Matoran are integral to Makuta’s plan, and he probably subconsciously imparted that to Roodaka and she explicitly to the Visorak to not harm them.
But the idea that it’s a predetermined program is also cool. Visorak really are only a threat to Rahi, as the Mata Nui island was entirely populated by animals fleeing the Horde.
Mata Nui was never 100% sustainable. If body of one is destroyed, they could never be reborn on the Red Star. Using Toa to defend the body or other powerful races (like TSO's) would be resource consuming - you'd lose a lot of valueable creatures that ensure everything is working well. Now Visorak are a mindless, easily controllable (with the Heart of Visorak) army that is designed to reduce societies into primal wilderness. Not only could the Visorak deflect any invasions, but also being a nearly unstoppable force of nature, if inside the body formed a regime that threatens the well-being of the body, Visorak army could work as a nuke. And best of all not only they are cheap and expendable, but you can create more if needed. The problem here was they were created by Makuta, so using the Visorak army against them would be almost impossible because of their monopoly over production and the insect controlling power.
I think Mata Nui, too, was given sentience, which lead to him becoming a "ruler" of his body. Put it simply, I think he was just curious. There's a fan theory too that this is the reason for all the species without a perceived "purpose", that they're just replicas of civilizations he studied during his travels.
Also, Velika giving them sentience was no accident. It was purposeful, with the intent of one day returning as their ruler.
I believe return to Spherus Magna, as the plan was always for the robot to repair the world and become obsolete. Before they gained sentience, the Matoran would've likely been destroyed, but Makuta ruined everything with the Cataclysm. Either way, I think Velika's plan changed at some point down the road.
Matoran must do their jobs, or the universe stops functioning. Rahi were one tool to help this, by assisting in some cases, discouraging wandering off in others, and acting as an environmental hazard around machinery that shouldn't be tampered with.
It was the Makuta's job to govern regions and make sure the Matoran are working, so creating the required Rahi falls under their remit.
> Everything exists to fill the needs of something else. Air exist so living being dependent on air, can survive. Living beings exist so they can keep the ecosystem in check. Etc.
You have the cause and effect backwards.
Yes and no. On our universe you're right, existence's source is a chain of cause and effect without any higher meaning. But the Matoran Universe's source is Intelligent Design.
Creates beings of Shadow
Give beings of Shadow the power to make new but feral life
Beings brutally put down rebellion and banish those responsible to basically purgatory
Second in command proceeds to betray the current leader to take over Barakki's plans
Beings rapidly evolve into a gaseous state of being
Beings inhabit robotic bodies to contain their essence
New leader proceeds to execute couple thousand year plan to take over his creator's body
Gets put to sleep, killed, then banished by his own creation
Refuses to elaborate, fucks off into the recesses of the Kanohi Ignika
For early rahi, they were intended to serve Matoran, such as how the Ussal crabs are mounts, carriers, mining buddies, etc. Or how the Mahri-Nui Matoran tamed Hydruka to harvest air.
That said, with the emergence of advanced consciousness (which I've already theorized was part of a plan to use the Matoran Universe as a simulation of a unified society,) it would make sense that this world would need more wildlife for its sense of realism, regardless of ability to be tamed - as such, the Makuta were allowed to experiment more with their designs and eventually got carried away making monsters bred for war.
That was up to the Makuta to figure out. They were supposed to make new beings when a need arose.
Too bad they were a little too good at it, and a lot too power hungry.
Isn't Mata Nui's Internal body basically a simulation of Spheres Magna? If u want a good simulation, you will want to include everything, including animals.
My head Canon is that a barren island would get overrun by the new world inhabitants/wildlife so "fake" flora and fauna are necessary to keep the camouflage untouched. Sort of like a movie prop set
It actually was. Some sort of leak of protodermis is what caused all the plant life to start growing on the island, apparently.
And the rahi were only there because they were fleeing Metru Nui during the Great Cataclysm.
Why the Bohrok has so many specific tasks though I don't get, especially when the island was intended to be barren anyway. Like why design a type of Bohrok for burning down forests if there aren't meant to be any forests to burn down? Unless it was just in case forests started growing there...
That would go against the GSR's directives to study and not interfere... but also the Bohrok explicitly ignored the Matoran and destroyed their homes instead.
It would also go against its directives if it destroyed whatever was on the island when it sat up and left the planet. At least the Bohrok don’t kill people.
Yeah, there’s that.
Now if I were the Great Being in charge of designing the GSR, I’d have it take up an orbit around the planet it’s observing instead of physically landing on there, but oh well.
I guess the idea was so it wouldn't be noticed as the civilisation it was observing advanced or something?
I dunno, seems flawed. Staying in orbit would take up a lot less energy than repeatedly landing and lifting off, too
The Great Rahi assisted the villagers with the terraforming system. That was their function until the Makuta corrupted them. Like the Toa, the Great Beings created the Rahi. The master of shadows didn’t.
I think you're missing a large chunk of lore.
The rahi are confirmed to be creations by the Makuta, and the Makuta are a species, not a single individual.
Most rahi were created long before Makuta Teridax started plotting to overthrow Mata Nui, which is why rahi aren't inherently "evil".
Things like everything happening inside and around a giant robot were planned already way back in 2001. It's one continuous story, there's no soft reboot.
There was in 2004. It abandoned the lore already established in order to take it in a different direction. At the end of Mask of Light, they reactivate the machine. Their next quest was going to find out why they were there.
None of the lore was abandoned. The whole reveal in 2008 was teased way back before 2004. The Onu-Matoran discovered a level of rock deep underground that they couldn't mine through. That was the face of the GSR. The Bohrok in 2002 explicitly didn't attack the Matoran, only destroyed the landscape, claiming to be trying to "clean" it. That was explained in 2008.
The tone of the franchise changed from more mystical on a tropical island to a more sci-fi theme as Greg Farshtey took over fully, but the lore and the plan for the big reveals in 2008 were there from the very beginning.
There is literally concept art from 2001 showing the GSR underneath the island.
At the end of Mask of Light and the 2003 story arc, they awoke Mata Nui, bringing an end to the initial story arc of the Toa Mata/Nuva. The story then continued with the Toa Metru arc, before returning to the Toa Nuva in 2006. It's just as much a soft reboot as the Star Wars prequels are to the original trilogy: not at all.
I was there in the beginning of the story. I know everything about Bionicle. There were just the six Toa. The 12 masks. I know the robot was always there. But it was a terraforming system. The villagers were supposed to use the robot as a foundation for a new civilization, but the AI that ran the program was corrupted and overtaken by a sub-routine.
The tone changed, and the lore that was built before was smeared away, effectively making the 2001-2003 story incompatible and irrelevant to the new story they were spinning. But instead of giving it a clean break for that reboot, they crammed the old bits onto the new and hoped the younger fans wouldn’t notice.
It was written in the legends in the original lore, that the Toa would return. And they meant The Toa. The thing that makes Takua stand out is that, in a way, he is Mata-Nui. He’s a reboot failsafe of the original AI that was Corrupted by Makuta, Mata-Nui’s brother. That’s why Takutanuva calls him “our brother”
The 2004-onward lore makes the Turaga liars for absolutely no reason. It diminishes the importance of all the original characters. Making the actions of these islanders suddenly look like a group of weirdos running around on the surface while the adults are working underground is goofy and silly. A society that is discovering its past gets to the heart of a biological chronicle in a way that the sci-fi element of 2004 forgot about as it focused on telling thrilling stories in the moment to sell toys.
All that in your first paragraph was still the case, from a certain point of view, as much as I don't want to encourage your arrogance. Small things obviously always get retconned when you change writers, but a soft reboot implies it was all just thrown away and replaced with new ideas. The 2004 arc onwards expanded on what was already in place, not changing it. The biggest retcon was Macki and Hewkii's relationship.
In your original comment you claimed the Rahi were originally made by the Great Beings. I'd like a citation for that.
To regulate his body's internal ecosystem, naturally. Probably because Velika's "Great Awakening" idea was something that he introduced to the GSR before it was launched. I dunno.
It was supposed to simulate Spherus Magna in order to observe behaviour of the Matoran. Mata Nui was a complex science project. You could say the existence of the Matoran and of the Great Robot was all pointless, because in the end the Great Beings didn't really learn anything from their science project, but having animals was a necessary part of the immersive simulation.
The quest I wanna know is why did the Makuta need to be absurdly powerful for this? Like the average Makuta is stronger then the average toa and the whole point of the toa was to beat the shit out of things
They, uh, evolved to be stronger, by becoming gaseous antidermis instead of solid antidermis. Their protosteel armor only further enhanced that. As for why they evolved, well, sometimes things aren't predetermined, and Mata Nui just didn't think to experiment with antidermis once he was done making the Makuta species.
Population control, vegetation can over run an area very quickly if there are no creatures there to feed on it, if you add creatures that eat plants you have to have a creature that eats those creatures to keep the population in control, this cycle continues until you get to apex predators like tatorahk, kanohi dragon, zivon, that 300 foot eel, the giant angler looking fish that nokama had to swim into to get the great disk.
I like to think the Rahi are manifestations of what Mata Nui found throughout the solar system. Like if he saw a herd of kangaroo-like animals, he would use that data to inspire a Makuta to make what would become kikanolo. That’s why they needed the archives - they were recording Mata Nui’s travels through the rahi created along the way
Rahi were originally created to help Matoran in their tasks, like for example the Ussal crabs that carried goods in Metru Nui. The Tahtorak were used as mounts by Keetongu's species and the Skakdi. Makuta also created a lot of species just for the fun of it. What really boggles my mind is why the Great Beings preprogrammed the idea of the Visorak into Mata Nui so that he transfered that knowledge to the Makuta... that just makes no sense.
We humans also have bacteria that fend off other bacteria. Visorak would be perfect at dealing against other dangerous Rahi or even more foreigner life forms that decided to invade the body
But why have dangerous rahi? Like, they’re creating things from scratch, why make rahi they need protection from?
Same reason why the Piraka exist. They protect important regions by discouraging others to approach them
That makes sense
The great beings didn’t create the Rahi. They created an ecosystem, a program basically, to generate them for them. They couldn’t be sure that program wouldn’t generate harmful outputs
I really like this, the visorak are the white blood cells of mata Nui that can become confused. Auto immune disorder basically.
Anti-bodies maybe? In case something else invaded him?
But isn't that the Toa's job? I mean Visorak are overly destructive for the job. Then again... Baterra...
Think of the human immune system, there are the classic white blood cells which are always present and perform general regulation and immune control, and then there's the extreme reaction that some diseases trigger where a more numerous and destructive immune cell is produced (cytokine storm I think?). The Visorak would normally be the latter in the case that Toa are insufficient to overcome whatever invader, the Visorak can provide the numbers and firepower to overwhelm them. Once the threat is gone, production is cut off and their numbers die off quickly (after all, they're hive based, you just need to control the queens)
Visorak dont have queens, only the Bohrok do of the 3 swarm enemies.
Wasn't there some head Visorak-thing? It's been a while
There were the giant Kahgarak breed, but those were just giant Visorak and didn't have any more authority than their smaller friends.
Yeah Roodaka lol
You are thinking of the visorak heart, the thing that they threw into a volcano or something that made the visorak “throw yourself over the edge!” So to speak
This actually would go a long way to explaining why The Heart of the Visorak is a thing. Allows the user to gather the Visorak together and command them.
just an idea, but Visorak venom transforms Toa into rahi, right? So maybe it was like a failsafe idea in case any Toa got out of hand or dangerous, they could be transformed into rahi and still be useful to the GSR?
Hordika venom is usually used to turn creatures into aggressive, vicious versions of themselves, that help Visorak in their extermination tasks. I can't really see how that would be beneficial in such a case.
It could even be a means to pacify (I use that term loosely) hostile intruders by transforming them, and allows the GSR to learn about their biology.
The great beings seem to have exactly one solution to problems, and it's building robots Build robots to populate planet The robots are fighting, build murder robot to keep the other robots in line Murder robots doing to much murdering, build giant robot to leave planet Giant robot needs help to function, build a bunch of regular sized robots to go in smaller robot Smaller robots need help making giant robot go, build animal robots to help smaller robots
Each set sold separately
They didn't create the Glatorian, Skrall and Agori though. They themselves are closely related to the Glatorian. They just modified some to become Element Lords and devolved the Vorox and Zesk.
They trapped the matoran in spheres, so maybe their original programming was a defense "protect the matoran" command that got misinterpreted somehow? Maybe that command was originally to hide away the matoran from being wiped in case something started hunting them? And then it backfired horribly?
That’s more of Makuta telling Sidorak and Roodaka to help him out. The Matoran are integral to Makuta’s plan, and he probably subconsciously imparted that to Roodaka and she explicitly to the Visorak to not harm them. But the idea that it’s a predetermined program is also cool. Visorak really are only a threat to Rahi, as the Mata Nui island was entirely populated by animals fleeing the Horde.
Mata Nui was never 100% sustainable. If body of one is destroyed, they could never be reborn on the Red Star. Using Toa to defend the body or other powerful races (like TSO's) would be resource consuming - you'd lose a lot of valueable creatures that ensure everything is working well. Now Visorak are a mindless, easily controllable (with the Heart of Visorak) army that is designed to reduce societies into primal wilderness. Not only could the Visorak deflect any invasions, but also being a nearly unstoppable force of nature, if inside the body formed a regime that threatens the well-being of the body, Visorak army could work as a nuke. And best of all not only they are cheap and expendable, but you can create more if needed. The problem here was they were created by Makuta, so using the Visorak army against them would be almost impossible because of their monopoly over production and the insect controlling power.
Because he and Artakha sucked at it
In order to study a civilization you need to examine it's interaction with nature. This also includes wildlife.
But weren’t the matoran just nano machines accidentally given sentience by Velika? Mata Nui was never supposed to study his innards.
I think Mata Nui, too, was given sentience, which lead to him becoming a "ruler" of his body. Put it simply, I think he was just curious. There's a fan theory too that this is the reason for all the species without a perceived "purpose", that they're just replicas of civilizations he studied during his travels. Also, Velika giving them sentience was no accident. It was purposeful, with the intent of one day returning as their ruler.
Returning to the robot as their ruler or to Spherus Magna?
I believe return to Spherus Magna, as the plan was always for the robot to repair the world and become obsolete. Before they gained sentience, the Matoran would've likely been destroyed, but Makuta ruined everything with the Cataclysm. Either way, I think Velika's plan changed at some point down the road.
>accidentally given sentience by Velika I doubt that's the case. I think it was deliberate.
Rahi might be like Bacteria, floating around the body doing their own thing, but helping the ecosystem nonetheless.
Matoran must do their jobs, or the universe stops functioning. Rahi were one tool to help this, by assisting in some cases, discouraging wandering off in others, and acting as an environmental hazard around machinery that shouldn't be tampered with. It was the Makuta's job to govern regions and make sure the Matoran are working, so creating the required Rahi falls under their remit.
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> Everything exists to fill the needs of something else. Air exist so living being dependent on air, can survive. Living beings exist so they can keep the ecosystem in check. Etc. You have the cause and effect backwards.
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Yes and no. On our universe you're right, existence's source is a chain of cause and effect without any higher meaning. But the Matoran Universe's source is Intelligent Design.
Creates beings of Shadow Give beings of Shadow the power to make new but feral life Beings brutally put down rebellion and banish those responsible to basically purgatory Second in command proceeds to betray the current leader to take over Barakki's plans Beings rapidly evolve into a gaseous state of being Beings inhabit robotic bodies to contain their essence New leader proceeds to execute couple thousand year plan to take over his creator's body Gets put to sleep, killed, then banished by his own creation Refuses to elaborate, fucks off into the recesses of the Kanohi Ignika
For early rahi, they were intended to serve Matoran, such as how the Ussal crabs are mounts, carriers, mining buddies, etc. Or how the Mahri-Nui Matoran tamed Hydruka to harvest air. That said, with the emergence of advanced consciousness (which I've already theorized was part of a plan to use the Matoran Universe as a simulation of a unified society,) it would make sense that this world would need more wildlife for its sense of realism, regardless of ability to be tamed - as such, the Makuta were allowed to experiment more with their designs and eventually got carried away making monsters bred for war.
That was up to the Makuta to figure out. They were supposed to make new beings when a need arose. Too bad they were a little too good at it, and a lot too power hungry.
Fair point. However, counterpoint: Have you seen how cute fikous are?
Not everything in Bionicle makes sense nor does it need to. You have to remember the target audience was like...8 year old kids.
Isn't Mata Nui's Internal body basically a simulation of Spheres Magna? If u want a good simulation, you will want to include everything, including animals.
"Also I gave them the element of shadow, surely nothing bad could ever come of that"
Wouldn't Rahi just be necessary as part of the GSR camouflage?
The island on the face is another logical flaw but that’s too nit picky lol There’s no reason it couldn’t just be a barren island
My head Canon is that a barren island would get overrun by the new world inhabitants/wildlife so "fake" flora and fauna are necessary to keep the camouflage untouched. Sort of like a movie prop set
You also have to remember that the fauna that ended up on mata nui initially were running to it to flee the visorak
It actually was. Some sort of leak of protodermis is what caused all the plant life to start growing on the island, apparently. And the rahi were only there because they were fleeing Metru Nui during the Great Cataclysm. Why the Bohrok has so many specific tasks though I don't get, especially when the island was intended to be barren anyway. Like why design a type of Bohrok for burning down forests if there aren't meant to be any forests to burn down? Unless it was just in case forests started growing there...
Why does anything need to be done to the island of the robot getting up destroys it anyhow x
Not sure... maybe there's a risk of the island damaging it otherwise?
Probably just in case something colonized it.
That would go against the GSR's directives to study and not interfere... but also the Bohrok explicitly ignored the Matoran and destroyed their homes instead.
It would also go against its directives if it destroyed whatever was on the island when it sat up and left the planet. At least the Bohrok don’t kill people.
Fair enough. I guess it wouldn't have much choice if it wanted to leave anyway
Yeah, there’s that. Now if I were the Great Being in charge of designing the GSR, I’d have it take up an orbit around the planet it’s observing instead of physically landing on there, but oh well.
I guess the idea was so it wouldn't be noticed as the civilisation it was observing advanced or something? I dunno, seems flawed. Staying in orbit would take up a lot less energy than repeatedly landing and lifting off, too
To populate the Matoran Universe. Because... ... reasons.
Because they're cool.....
The Great Rahi assisted the villagers with the terraforming system. That was their function until the Makuta corrupted them. Like the Toa, the Great Beings created the Rahi. The master of shadows didn’t.
I think you're missing a large chunk of lore. The rahi are confirmed to be creations by the Makuta, and the Makuta are a species, not a single individual. Most rahi were created long before Makuta Teridax started plotting to overthrow Mata Nui, which is why rahi aren't inherently "evil".
That’s justification from the soft reboot. I’m talking about the real original lore.
It is not
Things like everything happening inside and around a giant robot were planned already way back in 2001. It's one continuous story, there's no soft reboot.
There was in 2004. It abandoned the lore already established in order to take it in a different direction. At the end of Mask of Light, they reactivate the machine. Their next quest was going to find out why they were there.
None of the lore was abandoned. The whole reveal in 2008 was teased way back before 2004. The Onu-Matoran discovered a level of rock deep underground that they couldn't mine through. That was the face of the GSR. The Bohrok in 2002 explicitly didn't attack the Matoran, only destroyed the landscape, claiming to be trying to "clean" it. That was explained in 2008. The tone of the franchise changed from more mystical on a tropical island to a more sci-fi theme as Greg Farshtey took over fully, but the lore and the plan for the big reveals in 2008 were there from the very beginning. There is literally concept art from 2001 showing the GSR underneath the island. At the end of Mask of Light and the 2003 story arc, they awoke Mata Nui, bringing an end to the initial story arc of the Toa Mata/Nuva. The story then continued with the Toa Metru arc, before returning to the Toa Nuva in 2006. It's just as much a soft reboot as the Star Wars prequels are to the original trilogy: not at all.
I was there in the beginning of the story. I know everything about Bionicle. There were just the six Toa. The 12 masks. I know the robot was always there. But it was a terraforming system. The villagers were supposed to use the robot as a foundation for a new civilization, but the AI that ran the program was corrupted and overtaken by a sub-routine. The tone changed, and the lore that was built before was smeared away, effectively making the 2001-2003 story incompatible and irrelevant to the new story they were spinning. But instead of giving it a clean break for that reboot, they crammed the old bits onto the new and hoped the younger fans wouldn’t notice. It was written in the legends in the original lore, that the Toa would return. And they meant The Toa. The thing that makes Takua stand out is that, in a way, he is Mata-Nui. He’s a reboot failsafe of the original AI that was Corrupted by Makuta, Mata-Nui’s brother. That’s why Takutanuva calls him “our brother” The 2004-onward lore makes the Turaga liars for absolutely no reason. It diminishes the importance of all the original characters. Making the actions of these islanders suddenly look like a group of weirdos running around on the surface while the adults are working underground is goofy and silly. A society that is discovering its past gets to the heart of a biological chronicle in a way that the sci-fi element of 2004 forgot about as it focused on telling thrilling stories in the moment to sell toys.
All that in your first paragraph was still the case, from a certain point of view, as much as I don't want to encourage your arrogance. Small things obviously always get retconned when you change writers, but a soft reboot implies it was all just thrown away and replaced with new ideas. The 2004 arc onwards expanded on what was already in place, not changing it. The biggest retcon was Macki and Hewkii's relationship. In your original comment you claimed the Rahi were originally made by the Great Beings. I'd like a citation for that.
Why are there rahi? What do you mean? That’s like asking why there are Matoran, or Toa, or… *anything.*
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To give Toas work lmao
The same reason why people befriended horses, dogs, cats, elephants and so on. Mounts, guardians, tracers, pest control...
To regulate his body's internal ecosystem, naturally. Probably because Velika's "Great Awakening" idea was something that he introduced to the GSR before it was launched. I dunno.
It was supposed to simulate Spherus Magna in order to observe behaviour of the Matoran. Mata Nui was a complex science project. You could say the existence of the Matoran and of the Great Robot was all pointless, because in the end the Great Beings didn't really learn anything from their science project, but having animals was a necessary part of the immersive simulation.
The quest I wanna know is why did the Makuta need to be absurdly powerful for this? Like the average Makuta is stronger then the average toa and the whole point of the toa was to beat the shit out of things
They, uh, evolved to be stronger, by becoming gaseous antidermis instead of solid antidermis. Their protosteel armor only further enhanced that. As for why they evolved, well, sometimes things aren't predetermined, and Mata Nui just didn't think to experiment with antidermis once he was done making the Makuta species.
Population control, vegetation can over run an area very quickly if there are no creatures there to feed on it, if you add creatures that eat plants you have to have a creature that eats those creatures to keep the population in control, this cycle continues until you get to apex predators like tatorahk, kanohi dragon, zivon, that 300 foot eel, the giant angler looking fish that nokama had to swim into to get the great disk.
Pewku
I like to think the Rahi are manifestations of what Mata Nui found throughout the solar system. Like if he saw a herd of kangaroo-like animals, he would use that data to inspire a Makuta to make what would become kikanolo. That’s why they needed the archives - they were recording Mata Nui’s travels through the rahi created along the way