After the Quarter Knights lost one of its own, a replacement was needed. The Executioner, Boomerang was that replacement. The Metal Demon only had one desire in life, to hunt for the perfect prey. So strong was his desire that Lucied was drawn towards him despite being on opposide sides of the Demon War war.
With the strength of his heritage and an almost human-like spirit burning inside him, Boomerang is one of the deadliest Metal Demons to ever grace the DL. While he may not have his constant companion beside him, his Saber Fang is more than enough to dispatch all but the strongest of foes.