Quote Originally Posted by Mr.Bookworm View Post
Not to mention that he has statted out the Keys, and the comic does pretty explicitly run on Exalted mechanics. So they do need to at least mechanically work.
Not quite. Yeah, it's based on the rules, but the author has said that it's only loosely based on them. Most recently in this post.
Quote Originally Posted by Yuki Akuma View Post
The five Keys together are the only thing capable of punching through Perfect Defenses.

Until just recently, there weren't even five Keys. And no one has ever gathered even four of them.

No one has ever broken a Perfect Defense before.

See where this is going?

Nothing about the setting has been broken.
Actually, they do have a point; the keys simply give access the the powers the god of Locks had. So, yeah, that would be a kink in the setting.