Limitless The Strongest Revenant

After a life of regret, a loser dies and is reincarnated as a Revenant, beings who defend the living from the dead in exchange for a second life and a cheat ability. His own cheat, "Rewind," offers no combat advantage, leading to a near-death experience on his first mission. Determined not to repeat past mistakes, he vows never to bow to anyone again. Rejecting the traditional sword-wielding methods of other Revenants, he embraces modern weaponry, using guns to fight the undead. Surprisingly, "Rewind" allows him to perpetually have ammunition, enabling him to earn millions by eliminating zombies and liberating hellish territories. This wealth unlocks greater "Freedom," allowing him to deploy advanced technology from mortars to nukes, steadily pushing back the undead. Along the way, he saves seven beautiful women, all of whom fall obsessively in love with him, forming his "battle harem." He discovers he can gain their cheat abilities by exchanging bodily fluids, accumulating eight cheats in total. His second life, now a legend, sees him known as "Limitless," the Strongest Revenant.