Quote Originally Posted by SaberMaxwell View Post
So don't equip your characters with the same titles, don't equip the same event gear, throw it away and pretend you don't have them. You can create the illusion they're separate entities even if achievements were shared across characters
No, you really can't, because those achievements would no longer exist once the game regarded them as completed. You no longer have the chance to earn rewards once you already have them.