I Will Be the Pinnacle in the End of the World

In a closed room, a corpse that had just died was covered with blood all over its body. Cells are replenishing that shriveled body at a speed visible to the naked eye. Body... "Ugh, I feel so uncomfortable. I feel like my whole body is rotten* "like" The male protagonist who has traveled through time is waking up. Facing a strange world and various zombies and beasts, how will he face it in the future? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.