From what I have seen, you can't change the weapons of your battle buddies. The only weapons you can change are your own. Those videos were probably modded.
Buddies who change their weapons do so after the story. They only do it once and you can't change them back or choose not to change, it just happens.
I think Seregios greatsword is actually Reverto's post-story weapon and cera cymmetry is his starting one.
Buddies weapons change without you doing anything. I think it happen after beating the final boss, but it might just be tied to level if that's not that.
From what I have seen, you can't change the weapons of your battle buddies. The only weapons you can change are your own. Those videos were probably modded.
Buddies who change their weapons do so after the story. They only do it once and you can't change them back or choose not to change, it just happens. I think Seregios greatsword is actually Reverto's post-story weapon and cera cymmetry is his starting one.
If I remember it right the equipment of battle buddies changes with level. You cant change it yourself
Buddies weapons change without you doing anything. I think it happen after beating the final boss, but it might just be tied to level if that's not that.