Toaru Kagaku no Accelerator

Accelerator may still be Academy City's strongest Level 5 esper, but a severe injury has left him dependent on a device that supports his damaged brain. He wants nothing more than to recover quietly beside Last Order, the young Misaka clone he has sworn to protect.

That peace ends when Esther Rosenthal, a mysterious necromancer, draws him into a conflict involving a rogue organization operating inside Anti-Skill. Their experiments place the Misaka network and innocent lives at risk, forcing Accelerator back into the darkness he understands best. He calls himself a villain, but when someone targets the people under his protection, his terrifying power becomes the last thing standing between them and a far worse kind of evil.