In the End of the World, the Summoned Beast Is a Black Cat

Traveling through the apocalypse, I awakened the most useless contracted beast - the black cat who can only eliminate the sense of existence. The whole school laughed at me for being a "transparent person", but I laughed. There are gold belts for killing people and setting fires, but there are no corpses for repairing bridges and repairing roads. While the strong men were fighting bloody battles on the front line, I was taking my cat for a walk... In the enemy's lair.