Quote Originally Posted by Duelle View Post
I can't picture a Samurai with an invincibility. Same for Beastmaster, and same for Mystic Knight. On a concept level it doesn't look right.
I guess I'm still not seeing the problem. Invincibility is game breaking design to you in a way that's not clear to me.

I can envision abilities for samurai, beastmaster, and mystic knight that could make them invincible by not taking damage, instantly recovering, refusing to die, avoiding hits, etc. Samurai dazzles or interrupts attacks with a gil barrage or performs so many feints no attack can get through, beastmaster summons something to intercept hits for a few seconds, mystic knight drains a crystal/uses a rune to enhance their defense or imbue their blade to intercept/absorb all attacks, etc.

If you want to have an ability that gives limited invincibility, you can come up with an excuse without affecting the rest of the class design.