Blame!: Denki Ryoushi Kiken Kaisou Dasshutsu Sakusen

A vast, self-expanding structure of steel and rust has grown for years without a known purpose. Within this technological wasteland, a group of humans called the Electrofishers struggle to survive. Facing near extinction, they encounter a traveler named Killy. His arrival raises questions about whether he will bring destruction or salvation to the Electrofishers.