Koshtchtchie

The Demon Prince of Wrath. He once was a human who was both physically and spiritually ugly and was driven out of his homeland. He met Baba Yaga  who gifted him some stacked skull jars to keep his soul in. As long has he kept the skulls intact he was immortal. He promptly used this new found immortality to wreak terrible vengeance on those who exiled him and then continued to conquer and pillage the land.  The gods finally had to intervene and cast him into the Abyss where he rose through the ranks to become and arch-demon.