666 Satan

In a near-future world, humanity is locked in conflict over O-Parts—ancient relics left behind by a lost civilization. These remnants possess immense power, but only a rare few can unlock their true potential. Known as O.P.T.s (O-Parts Tacticians), these individuals wield abilities that can reshape the world, for better or worse. Jio is a young boy shaped by a painful past, trusting nothing and no one except money. Unbeknownst to him, he is an exceptionally powerful O.P.T., and within him dwells a ferocious demon of unimaginable strength. His path crosses with Ruby, a determined girl with dreams of her own. Together, they set out on a perilous journey to uncover as many O-Parts as possible. Along the way, Jio may hold the key to Ruby's ambition of becoming a legendary treasure hunter—but the greater question is whether Ruby can help Jio achieve his own startling goal: world domination.