Quote Originally Posted by Kawaii Ryűkishi
All life came from the Crystal, and at the beginning of it all, Necron was also created. His task was to watch all living creatures until he received a sign that life didn't feel like existing anymore, at which point he'd return everything to nothingness. Kuja's extremely nihilistic acts towards the end of the game had Necron convinced that this was his sign--that, deep down, living things wanted to die, and that Kuja's actions were a reflection of this. And he would have erased everything right there, too, except Zidane and company were there to convince him (with swords and fire) that no, screw what Kuja thought, they wanted to keep living. Necron took the hint and went back to ineffectually waiting for his cue.