Demon Sect Master Forces Me to Guard the Hell Prison

Evan Lin, an elder of the Heavenly Demon Sect, became useless after failing to break through to the Nascent Soul realm. Sent to the Hell Prison by his beautiful junior sister Su Qinghan, who cultivates the path of Emotionlessness, he faces his dying years until he accidentally awakens the Ultimate Idle System. By simply staying alive, he gains ten years of cultivation daily and unlocks a divine identification technique to reveal deadly secrets. In secret within the prison, Evan fuses the Supreme Immortal Bone, recasts his flawless Golden Core, and steals demonic blood to awaken tenfold combat power. When his sect faces betrayal and an ancient blood demon descends to slaughter the world, the former 'useless old man' transforms into a supreme demon god, securing his beloved wife, slaying rebels, and suppressing evil spirits, embarking on an unstoppable path of dominance!