My Monster Fuses Everything

Apocalypse befell, and roommates performed a skyward ritual.

As the fog descended, the Book of Blood Spirit appeared in the hands of all survivors, and only those with a Contract monster could survive.

Su Han directed his gaze to the neighbor who had already mutated and twisted, silently pulling out a gleaming fruit knife...

Grotesque meat corpses, giant spiders with gaping mouths, eyeballs enveloping the city, one-eyed sharp-toothed hand monsters...

Civilization fell, cities shattered, and all humans became meat for the monsters. There was only one way to survive:

Use monsters to fight monsters.