Nightmare Cuphead is an aggressive kind of person, though he never really speaks when interacting with others. (Though it may be possible that he can talk.) This nightmare cup being is not a very approachable person, as his rage from his brother’s death fuels this form and power. There is no way to cool him down. Along with being super powerful, he’s also basically indestructible and is not harmed through attacks. Fighting him is a death wish, you won’t win if you tried.