The Specter Contractor

Specters arrive, devouring people. Male lead unlocks Ten-Thousand Wraith Contract System, signing pacts with Specters for superpowers and supplies. Other survivors flee, but human looters hunt those who bond with Specters. Hiding strength, hero subdues Specters for his spirit squad, crushes looter strongholds, uncovers truth behind apocalypse. He rises to supreme overlord, commanding Specters and protecting survivors.