Betrayed, I Met The Demon Lord Novel

Two reincarnates arrive in a magical realm with a single directive: slay the Demon Lord. Van struggles through his inadequate abilities, suffering through each battle and trial. Magus, blessed with overpowered gifts, thrives—accumulating a harem that eventually claims Van's beloved.

Victory comes at a terrible cost. Upon learning of his girlfriend's betrayal, Van's rage ignites. In a shocking twist of fate, he seeks out the very being they defeated, the Demon Lord himself, with an unexpected proposal that will redefine everything.