TheA Certainuniverse is well-known forits three long-runninganimeand massive cast of characters. In the main series,A Certain Magical Index, there are a total of three main heroes: Kamijou Touma, Hamazura Shiage, and Accelerator.
Related:A Certain Magical Index: The Order You Should Watch All The Anime Seasons

Of the three, Accelerator has had the most touchy anti-hero past, starting as one of the most popular antagonists before switching sides. Likewise, second to only Kamijou Touma (naturally as theanime’smain protagonist), Accelerator has some of the deepest lore amongst all characters — enough to warrant the creation of his own side series,A Certain Scientific Accelerator.
10Accelerator Is An Esper
The world ofA Certain Magical Index(and all ofits spin-off series) is defined by a clear divide between the science-based espers of Academy City, and the Magic Side found everywhere else. Accelerator is an esper, and therefore, tends to interact with other major players on the Science Side of the universe.
Accelerator’s ability is highly technical, requiring him to solve complex equations in physics to manipulate vectors. Using his ability, Accelerator can cause massive amounts of destruction, redirecting bullets, launching massive bars of steel, and even fatally injuring people just by touching them.

9Accelerator Is Academy City’s Number One
Just as Accelerator has a convenient ability, he also holds a high position in the politics of Academy City. Espers inA Certain Magical Indexare ranked in terms of level, with Level 0 Espers having no ability andLevel 5 Espershaving the most manipulative abilities.
There are a total of 7 recorded Level 5 Espers in Academy City, includingA Certain Scientific Railgun’smain heroine Misaka Mikoto (ranked 3rd of the 7). As for Accelerator, he is ranked first in terms of total power and usefulness.

8Accelerator Is From The Dark Side Of Academy City
Generally speaking, Academy City (the urban setting of theA Certainseries) has two faces which are explored directly in two of the three anime adaptations.A Certain Scientific Railgunfocuses on the “Light” Side of Academy City, where Misaka Mikoto works with Judgement to fight crime. However, while the criminal side is present in this adaptation,A Certain Scientific Acceleratorgives more focus to the Dark Side of Academy City.
Related:The Smartest Anti-Heroes In Anime
Given Accelerator’s past (as a participant of the Shift Experiment), he is directly a part of the Dark Side of Academy City. At first, Accelerator was a member of the Dark Side’s human experiments, however,A Certain Scientific Acceleratorfocuses on his anti-hero fight against criminal organizations like the Scavengers.
7Accelerator Is Enrolled In Nagatenjouki Academy
Whilehis delinquent-like appearancewould say otherwise, Accelerator is enrolled in a school within the constraints of Academy City. It may just be on the books (as Accelerator does not attend classes), butA Certain Scientific Accelerator’snamesake hero “attends” Nagatenjouki Academy.
While not as prestigious as Tokiwadai Academy, Nagatenjouki is considered one of the best schools in the entirety of Academy City. Interestingly, unlike the former, Nagatenjouki Academy does not discriminate between espers and non-espers — both attend the school regardless of their abilities.

6Accelerator Was The Victim Of Human Experiments
Without a doubt, in bothA Certain Magical IndexandA Certain Scientific Railgun,the Sisters Arc is considered to beone of the best. And one of the main factors for this popularity stems from the arc’s antagonist — the Sisters arc was the first appearance of Accelerator.
Here, Accelerator was forced to participate in the Level 6 Shift Project, in which he would be forced to kill 20,000 clones of Misaka Mikoto (the protagonist ofA Certain Scientific Railgun) — in doing so, he would be able to “level up” to a Level 6 Esper. Luckily, Accelerator was defeated here by the protagonist ofA Certain Magical Index, Kamijou Touma.

5Accelerator Has His Own Side Series
BothA Certain Magical IndexandA Certain Scientific Railgunare very well-known for the size of their light novel selection and the popularity of their anime, respectively. However, there is a third anime adaptation in the universe that focuses on the story of Accelerator,A Certain Scientific Accelerator.
Related:Side Characters Who Got Their Own Anime Or Manga Spin-offs

The (currently) one-season side series takes place around halfway throughA Certain Magical Index’sfirst season (just after the Sisters Arc and meeting Last Order, to be specific). Unlike its two counterparts,A Certain Scientific Acceleratordoes not focus too much on the Magic or Science Sides, rather including characters from both (including Esther Rosenthal, a necromancer that acts as the series’ main heroine).
4Accelerator Is Something Of A Babysitter
Along with Accelerator’s popularity in the series (and the anime andlight novel community in general), his companion Last Order also receives a lot of admiration from theA Certaincommunity. A member of the Sisters Network, Last Order is a young clone of Misaka Mikoto who acts as the master control of the network.
After her introduction, she quickly finds herself taken under Accelerator’s wings, with the latter acting as her guardian for her protection. As the series progresses, Accelerator grows a strong connection to Last Order — protecting the clone becomes Accelerator’s main objective throughoutA Certain Scientific Acceleratorand the late two seasons ofA Certain Magical Index.

3Accelerator Has An Unexpected Connection To The Magic Side
While Accelerator is typically seen as a Science-centric character, being the number one esper in Academy City, he does have a somewhat unexpected connection to the Magic Side of the series. Accelerator’s powers are stated to be connected to the plans of a major magical player in the series, considered by many to bethe “real” main antagonistof the entire universe, Aleister Crowley.
This would be a major connection for Accelerator between both the Magic Side and Kamijou Touma, who is also considered to be strongly related to Aleister Crowley’s plans. While not necessarily confirmed, most fans of the series support the idea that Accelerator’s mysterious angel-like powers (that take the form of wings like Kakine Teitoku, the Rank 2 Level 5 Esper).

2Accelerator Lost His Powers (Kind Of)
The events following the Sisters Arc represent a major shift in Accelerator’s role in the story, moving from an antagonist to an anti-hero that wants to use his to help others. Quite ironically, this shift in mindset initially shoots Accelerator in the back (actually, in the head). Following the incident with the Shift project, Accelerator meets Last Order — a child resembling Misaka Mikoto, who is actually the central hub of the Sisters network.
After Last Order is kidnapped shortly after, Accelerator comes to the rescue and is shot in the head by the scientist responsible for her capture, which causes his mental processes to fail to the extent of being unable to use his ability. Now, Accelerator must use a battery-powered electrode (ironically connected to the Sisters network) to use his ability, and this is whereA Certain Scientific Acceleratorstarts.

1Accelerator Was A Member Of GROUP
As a member of the Dark Side of Academy City, it only makes sense that Accelerator would become a participant in one of its most important events inA Certain Magical Index— the October 9th war (aka the Battle Royale Arc). The incident was a faction war between the Dark Side organizations at the time:
Of the five organizations, Accelerator is recruited into GROUP along with Tsuchimikado Motoharu, Etzali, and Musujime Awaki. GROUP answers to Academy City’s Board of Directors, and therefore perform jobs that are too malice and secret for organizations like Anti-Skill or Judgement.
