They really shouldn't bring him back, he was a really interesting/annoying character that should have died in Stormblood and his plot pretty much went nowhere. He was basically an attempt to be the "Blue/Gary" to your "Red/Ash", with the same kind of "I'm better then everyone" obnoxious personality, while channelling the edge and looks of Sephiroth without the mummy issues. He is better off dead and buried at this point.