The Omega Stone (石Ω, Ishi Omega) was an item discovered by Yasaki Hatake during his travels with his occasional teacher, Shinzui Uchiha. While in the Land of Fangs, observing the Mountains' Graveyard, Yasaki spotted the stone with his Sharingan. The stone had a distinctive chakra, akin to how someone's chakra appears when they are under the effects of genjutsu. Amazed at the object lodged in the bone, Yasaki took it from the bone, and later made it into a necklace. At the very moment Yasaki laid hands on it, the jewel integrated into Yasaki's inner being, forever connecting the two. In Akeya, the stone took a more darker form, becoming that of a spirit within the young man, Ōdō (横道; lit. Wickedness) .