Samurai Jack (2001)

S4E4 Birth of Evil

In a bid to eliminate a formidable evil, ancient gods launch a fragment of the beast into the cosmos. This shard crashes onto Earth, unleashing its malevolence across the land. As the darkness begins to invade his empire, an Emperor decides to confront this threat. However, in his attempts to eradicate the evil, he inadvertently releases Aku, the very embodiment of that dark force.