Accelerator is named after his ability. It creates a thin field of AIM around him, which allows him to modify the vector values of anything he touches. After the events of Volume 5, his brain has been damaged, and he has to rely on a choker-style electrode that connects him to the Misaka Network.

Accelerator's ability is based on Vector Transformation (ベクトル変換, Bekutoru Henkan?), known in other names such as Vector Change and Vector Conversion, that allows him to control vectors (magnitude and direction) and influence objects that have vectors such as bullets, heat, and electricity.

Accelerator first appears in Toaru Kagaku no Railgun, where during another session of brutally killing a Misaka clone, he meets an enraged Misaka Mikoto who tries to get revenge on him after she witnesses him killing Misaka 9982. However, Mikoto is powerless against Accelerator due to his abilities.

Kakine's ability to go through Accelerator goes like this: Acceletor's power is a wall that allows wooden horses. Kakine was able to get through by having his power act like a Trojan. Other things can also get through Accel's wall.

Accelerator's ability creates a thin field of AIM around him, which allows him to modify the vector values of anything he touches. After the events of Volume 5, his brain has been damaged, and he has to rely on a choker-type electrode that connects him to the Misaka network.