heh, i wouldn't call him hard, beat him without using subtanks.
his second form was predictable as hell. the only thing that even bothered me was getting frozen - and that only happens when i don't pay attention.
and i wouldn't say any RPG boss is hard...unless there's a limitation to experience points, all the bosses are easy, it just takes time.
MMX7, on the other hand...the whole game was just a friggin hassle to deal with...mainly due to poor game design.
Yea... it was almost imposible to grip onto platforms at times and fucking Glide mode would turn on at the worst instants for X...