The Son-in-Law's Everlasting Clan

Forget fighting for treasures; true power lies in the bedroom. Born talentless, Feng Muchen's only hope is a bizarre system that rewards him for every child he fathers, granting him their strength. So he marries into an immortal family as a lowly son-in-law to begin his unique cultivation journey. While others risk death for resources, Feng Muchen wages a different kind of war to forge a dynasty. But as his power grows with every new branch of his family tree, can he protect his lineage from a world that only respects the sword?