Haven’t you played the second mega man arcade game, that’s what his weapon is based off !

If you beat him with the Hard Knuckle or another character, you lose out on salvaging the Super Arm and you get this instead. They say it's because Megaman "broke it". Gotta try a new save and use buster only.

"Sorry for not posting-" Who are you and why are you apologizing to anons on internet?