On Blue Star, the card game 'Three Kingdoms Kill' has manifested as a deadly reality where defeat means instant erasure. Gu Xuan, a seasoned player from his past life, finds himself on the brink of death with zero currency after a teammate's catastrophic blunders. Just as elimination seems inevitable, a mysterious black gate labeled 'Underworld' awakens within his mind.

This cheat skill grants him access to a forbidden general pool filled with overpowered, ghostly variants of historical heroes that never existed in the standard game. While ordinary players struggle with basic strategies and pay exorbitant fees for weak characters, Gu Xuan can summon terrifying 'Yin' generals capable of crushing the meta. With only enough currency for one desperate draw before his next forced match, Gu Xuan must rely on his wits and this haunted arsenal to survive the lethal arena, turn the tide against ruthless opponents, and uncover the secrets of this death game.