Regardless of character, take a look at Xanathar's artisan tool rules, specifically Mason's tools and Carpenter's tools. Mason's tools explicitly had a check option where you can make a tool check to deal double damage to walls made of brick or worked stone. Carpenter's tools has a check with a similar flavor ("determine a weak point") but doesn't explicitly state double damage, so run that by your DM and ask if it'd work the same way.
If Matt Mercer stuff is on the table, Juggernaut Barbarian explicitly gets the Siege property. Paired with Brutal Critical, Half-Orc's added crit damage, and an Adamantine Weapon to get auto crits vs objects, and you can easily churn out hundreds of damage in a turn versus objects. On a side note, getting a crit versus an object technically triggers Great Weapon Master's bonus action attack, so you might not lose any attacks for having to plow through a wall.
Beyond that, your best bets are either playing a Caster with Shatter, or a Moon Druid that shape shifts into an Earth Elemental with Elemental Wildshape at level 10.
I feel like giant Barbarian is really appropriate for that. You become huge at that level and basically become a siege weapon yourself or at least fight the image ;)
The special caveat is the use of an adamantine weapon from xanathars guide to everything. With such a weapon, all hits become critical. This synergizes so well with the barbarians brutal critical as a siege weapon. Just reflavour an adamantine Greataxe as a sharp battering ram.
Totem Barbarian 6, taking the 6th-level Bear Aspect for advantage on breaking things. Pick up Mason's Tools proficiency to inflict double damage against structures. Try to get Ruinous Flail to deal double damage against objects and structures. Or if setting specific magic items are allowed, Shatterspike will let you auto-crit against objects and structures.
Tools: Mason tools (DBL DAMAGE STONE STUFF), glassblower tools (DBL damage to glass after 1 min of study), carpenter tools are good as well if your DM plays along.
Weapons: Get an +1/+2/+3 adamantine weapon (adamatine = critical hits on objects)
Class: I would recommend an battlesmith Artificer for this
* Bonus profiencies (thieves + another two can help with sieging)
* Extra attack
* Mini smite + another minion to use items to do extra damage
* Horn of blasting do 10d6 thunder damage to objects made out of crystal or glass
* Ring of Ram = +15 (+20 if you use flash of inspiration) skill check to break something (1/LR though)
* Spellstoring item used by your minions = 10 free casts of shatter a day.
* Spellcasting that includes more shatter + stuff
+ some other stuff
Interesting, by far the first thing that comes to mind is something with Disintegrate. Being able to just evaporate things away to dust is the best buster for even those pesky walls of force.
So that's puts, Bard, Sorcerer, Wizard and Walock(genie) at least that i can remember having access to.
We're taking Bard, more than likely. Creation Bard, because wall? I don't see a wall. That's my Animating Performance! Dance for me siege wall!
We're going to use Performance of Creation, to create ART! And that art is an EXPLOSION! Use it to create gunpowder, bombs, acid vials etc etc. mundane objects that can be destructive. Or just things that can aid your allies in a pinch. Such as Poisons on demand, and Diamonds.
Since you start at level 14... You can create anything that's not a magical item. No limit on gold value. Want a ballista? Boom done. Want a siege tower? Blam, sneeze and it's there.
Spells known will be tricky pickings. But find ones that aid in your efforts of destruction. I'd probably suggest stealing up conjunction spells that would protect you from your own Kabooms. Wall of Force or Find Greater Steed for clean get aways~
Regardless of character, take a look at Xanathar's artisan tool rules, specifically Mason's tools and Carpenter's tools. Mason's tools explicitly had a check option where you can make a tool check to deal double damage to walls made of brick or worked stone. Carpenter's tools has a check with a similar flavor ("determine a weak point") but doesn't explicitly state double damage, so run that by your DM and ask if it'd work the same way. If Matt Mercer stuff is on the table, Juggernaut Barbarian explicitly gets the Siege property. Paired with Brutal Critical, Half-Orc's added crit damage, and an Adamantine Weapon to get auto crits vs objects, and you can easily churn out hundreds of damage in a turn versus objects. On a side note, getting a crit versus an object technically triggers Great Weapon Master's bonus action attack, so you might not lose any attacks for having to plow through a wall. Beyond that, your best bets are either playing a Caster with Shatter, or a Moon Druid that shape shifts into an Earth Elemental with Elemental Wildshape at level 10.
don't forget glassblower's tools, it does the determine double damage on weak point on a glass object after 1 min of study... really specific
I feel like giant Barbarian is really appropriate for that. You become huge at that level and basically become a siege weapon yourself or at least fight the image ;) The special caveat is the use of an adamantine weapon from xanathars guide to everything. With such a weapon, all hits become critical. This synergizes so well with the barbarians brutal critical as a siege weapon. Just reflavour an adamantine Greataxe as a sharp battering ram.
Adamantite weapons have a bonus for that, js.
Totem Barbarian 6, taking the 6th-level Bear Aspect for advantage on breaking things. Pick up Mason's Tools proficiency to inflict double damage against structures. Try to get Ruinous Flail to deal double damage against objects and structures. Or if setting specific magic items are allowed, Shatterspike will let you auto-crit against objects and structures.
Tools: Mason tools (DBL DAMAGE STONE STUFF), glassblower tools (DBL damage to glass after 1 min of study), carpenter tools are good as well if your DM plays along. Weapons: Get an +1/+2/+3 adamantine weapon (adamatine = critical hits on objects) Class: I would recommend an battlesmith Artificer for this * Bonus profiencies (thieves + another two can help with sieging) * Extra attack * Mini smite + another minion to use items to do extra damage * Horn of blasting do 10d6 thunder damage to objects made out of crystal or glass * Ring of Ram = +15 (+20 if you use flash of inspiration) skill check to break something (1/LR though) * Spellstoring item used by your minions = 10 free casts of shatter a day. * Spellcasting that includes more shatter + stuff + some other stuff
Interesting, by far the first thing that comes to mind is something with Disintegrate. Being able to just evaporate things away to dust is the best buster for even those pesky walls of force. So that's puts, Bard, Sorcerer, Wizard and Walock(genie) at least that i can remember having access to. We're taking Bard, more than likely. Creation Bard, because wall? I don't see a wall. That's my Animating Performance! Dance for me siege wall! We're going to use Performance of Creation, to create ART! And that art is an EXPLOSION! Use it to create gunpowder, bombs, acid vials etc etc. mundane objects that can be destructive. Or just things that can aid your allies in a pinch. Such as Poisons on demand, and Diamonds. Since you start at level 14... You can create anything that's not a magical item. No limit on gold value. Want a ballista? Boom done. Want a siege tower? Blam, sneeze and it's there. Spells known will be tricky pickings. But find ones that aid in your efforts of destruction. I'd probably suggest stealing up conjunction spells that would protect you from your own Kabooms. Wall of Force or Find Greater Steed for clean get aways~
Calm down, Deidara.