Cold-Blooded Umewakamaru

S1 E8: In the Heian period, Umewakamaru was born into a noble family. He was gifted young man exceling in fencing and academics. However, one day, he is informed that his mother is seriously ill. Umewakamaru immediately heads for Mt. Nejireme where his mother is supposedly recuperating. But he arrives only to witness his mother’s cruel death. Mourning the death of his mother at the hands of Gyuki, Umewakamaru curses the world and kills everything from humans to yokai. Eventually, his ruthlessness leads him to be called Gyuki himself.