"I'm a protector adept" or "I'm a great bear adept" both sound really confusing to me, unless those are recognised institutions in-game. "Great Bear Adept" is fine if it means something like "Adept of the Great Bear fighting style". As generic terms I think they're really poor. Personally I'd cut to the chase: "I'm a Defender!"

Or if you like 'adept', how about "I'm a Guardian adept" vs "I'm a Greatweapon adept". Again, personally I would cut out the word 'adept', which I don't think adds any information and has unwelcome connotations in a Western-fantasy game. It makes me think of either sorcery or kung fu.