Betrayed by his girlfriend in the apocalypse, the protagonist activates the 'Omni-Synthesis System' on the brink of death. Fusing zombies with items, he builds his undead army. As his power grows, he defeats the Blackwater Legion, triggering a world-ending crisis—the world reset program. Facing the SS-Class World Devourer, Linden fights alongside his army, completing a final fusion to defeat it and save the world.