Hmmm, he should be a strong fighter obviously, but some of the special abilities are a bit 'gamey'. For example, Old Soldier is definitely over-powered, maybe just make it so that it only gives a big advantage in a fight? From what I read, this game is more about role-playing and describing how you/the Knight fight rather there being strict tiers of what beats what. The only other problem is with the Silver Horn, maybe change it so that it only gives the Knight a rough idea of where Thomas is and also produces a very loud sound - 'summon' is a bit too strong I think.

Take what I say with a pinch of salt though, since I deliberately made my character very underpowered (I can throw potions and cast acid splash...)