ballos
Ballos is the true final boss of Doukutsu Monogatari/Cave Story. He has 4 phases: one in his human form and three in his circular form. He is the creator of the Demon Crown and its curse, that of which is nullified after the events of the best ending. He is the uncle to Misery and the younger brother of Jenka. He was once kind and caring to all those around him, using his magic to the benefit of all. The king of that land grew jealous and then imprisoned Ballos, where the resulting torture push Ballos' magic to its limit. The rest is history, and Jenka was more-or-less forced to seal her brother away.
Ballos is fully aware of all of this, and desperately wants to die. Will you grant him this mercy, Quote and Curly?