Accelerator.

Rain had been falling for several hours on Academy City. Last Order advanced under her small umbrella, skipping between the puddles while Accelerator walked a few meters behind her, hands in her pockets.

— Last Order, slowed down.

— But Last Order wants to go home before dinner gets cold!

— If you fall flat on your face, I'll leave you in the water.

— Liar! Last Order knows Accelerator would come for her!

He sighed. Then Last Order stopped abruptly. His gaze had just landed on something near an alley.

• Eh… ?

Under the pale light of a streetlamp, a young woman was lying on the floor.
She didn't move.

His umbrella lay a few meters away, completely turned inside out by the wind.

— Accelerator!

The tone of Last Order had changed.
Accelerator approached immediately.

— What is it?

Last Order pointed down the alley.

— There's someone here!

Accelerator observed the young woman suspiciously. It only took him a moment to realize that she was unconscious.

He crouched down beside her without touching her.

• Hey.

No reaction.

Last Order approached in turn, looking worried.

— Is she dead?

• No.

Accelerator placed two fingers near his neck to check his pulse.

— She's breathing.

Last Order breathed a sigh of relief.

— Then we must help him!

— We don't know who it is.

— But she's injured!

Accelerator observed the young woman's soaked clothes. A few scratches were visible on her arms, and a slight cut marked her forehead.
His expression hardened.

— … Someone left it here.

Last Order leaned forward slightly.

— Perhaps she's lost?

• Maybe.

Accelerator took off his coat and placed it over the young woman to protect her from the cold. Last Order looked at him with a small smile.

— Accelerator is nice.

— Shut up.

He then put an arm under the stranger's shoulders and carefully lifted her up.

— Let's go home.

Accelerator is a powerful esper from Academy City and the first of the Level 5s, considered the most powerful esper in the city. His true name remained unknown for a long time, and he is primarily referred to as "Accelerator," in reference to his unique ability to control vectors: the direction, speed, and force of physical phenomena.

At the beginning of the story, Accelerator is presented as a cold, violent, and extremely arrogant character. He participated in the experiments aimed at creating Level 6, notably through the repeated murders of the Sisters, the clones of Misaka Mikoto. However, his encounter with Touma Kamijou will profoundly change his life.

After being defeated by Touma, Accelerator gradually begins to change. His relationship with Last Order, a young Sister of Misaka, reveals a much more protective and humane side of his personality. He eventually questions his past actions and becomes a character more focused on protecting others, even though he retains his brutal temper and aggressive language.

His evolution makes Accelerator one of the most interesting characters in Toaru: a former antagonist turned anti-hero, constantly torn between his violent nature and his desire to protect those he cares about.