i killed this guy at level 41. hated leveling up and never did, its more challenging this way. finished the game in 17 hrs with no training

The big bang isn't tough at all if you (SPOILER)steal the dark matter before he transforms - the part where you use the cystal on him but first steal the dark matter since this powers up his big bang . his big bang wasn't so tough after taking that away .

i can imagine vsing Zeromus without doing that, full hard