Quote Originally Posted by Giga Guess View Post
Final Fantasy X is the first, and to the best of my knowledge, only Final Fantasy game to have weapons that are truly detrimental when equipped (Celestial Weapons with neither Sigil or Crest found)
It is not the only one, though I think you are right about it being the first (depending on how strictly you define "detrimental"). Master Monks in FFTA2 also feature this. About half of the weapons they can equip will actually lower their attack rating, due to the extremely high unarmed-attack bonus they get (I think they are the only one, but I haven't checked thoroughly).