I Reincarnated As The Hero's Childhood Friend (Ex-Demon General)

Artpe, the weakest of the Demon King's Four Heavenly Kings, just wanted a quiet life. Instead, his pathetic existence ended on the Hero's blade. But death wasn't an escape; he was reborn as a human child, cursed with retaining his past life's memories and his unique ability: Read All Creation, now evolved! Armed with perfect knowledge of every hidden dungeon, legendary treasure, and future event, Artpe’s new goal is simple: power-level the future Hero (and himself) to obliterate the Demon King and finally secure his peaceful, cow-farming retirement. The problem? He’s reincarnated as the Hero’s childhood friend, an overly attached, terrifyingly overpowered girl. Worse, during his baptism ritual, the unthinkable happened: Artpe himself was chosen as a Hero! Now, this ex-demon general is stuck leading the very crusade he wanted to avoid.