Well X isn't the villain in the Zero series.The villain is Copy X.He was a copy of the original X that Ciel created.Because the original X was missing or guarding the dark elf like it was shown in MMZ2 he was guarding the dark elf in his sleep.But still if X were the villain in the zero series it would have been awesome.So yea pretty much X would have been a great villain in the Zero series if he was the original X...but alas the villain is copy X.And when Elpizo or whatever his name is...destroyed the dark elf's prison along with the original X thus ending X's existence but X lived on as an elf as well...in MMZ3 it was proven that X was still alive but he left at the end of Zero 3.Still if the original X was the villain he would be a lot stronger...copy X is a very inferior copy to the original X.The original X's armor was a lot better then the copy's armor...the original X had like a billion armors before and somehow he loses them all the time.That question remains...how does X lose all of his armors after every single X game?Sill copy X is extremely weaker then the original X thus proving that the X in the zero series is a copy.Except the one that was keeping the dark elf sealed up but Elpizo or whatever his name is blew up the original X also the dark elf's imprisoning and that is how X was gone from the zero series but in MMZ3 X appeared as an elf i think...But in MMZ3 he also left.And still if the original X was the villain it would be a lot harder to fight him...seriously.