thorn (weapon) (tower of god)

Enryu's Thorn (엔류의 가시, Enryu-ui Gasi), also referred to as The Real Thorn, The King Slaying Thorn, The Thorn to Kill the King or simply the Thorn, is a gigantic and massive red, diamond-shaped object that was first discovered by a person with strange eyes on the 43rd Floor, the location where Enryu killed a Floor Administrator, known as the event Enryu's Massacre.