Accelerator/Personality and Relationships

Personality
Due to the potential of his ability, Accelerator has been targeted by assassins and researchers throughout his life. As a result, he only believes in power and trusts no one. He also became a jolly and mocking, yet also twisted and maniacal person. While fighting, he invokes fear and has a sadistic tone. He willingly joins the SISTER experiment to gain a reputation as the most powerful and feared esper so that no one would dare to be foolish enough to challenge him and won't hesitate to kill anyone who gets in his way. The Sisters' memories of his behavior during the experiment may suggest that he is, in a way, a pacifist; because his power won't disappear, the only way he sees an end to the fighting is to be so strong and sadistic that no one would dare to raise a finger against him. He even seems to attempt to frighten the Sisters out of fighting or otherwise encourage them to refuse their battles.

After meeting Last Order, he strives to protect her. He saved her from Amai Ao's plot and from being pursued by the Hound Dogs. He treats Index in a similar fashion, such as when he buys her lunch while searching for Last Order and by protecting her from the Hound Dogs. By Volume 19, he has mellowed out to the point that he actually lectures a child in order to prevent him from getting himself killed after a hostage situation. In spite of this, he does so in a violent way. In volume 15 he styles himself as the perfect villain in contrast to Touma being the ideal hero. However, despite his words, there is no mention in the narration that he has killed anyone and goes out of his way to incapacitate only his enemies up until his battle with Kakine, who challenges his contradictory way of thinking. This contrast with Touma is hinted at throughout the novels after Volume 5 when it is shown that he both idolizes and is slightly jealous of Touma's heroic personality, and is outright shown when he and Touma finally come to blows in Volume 20. By comparison according to Heaven Canceller, Touma and Accelerator are very similar, but their methods are like opposite sides of a coin; Touma is able to protect his loved ones without killing and is able to stand by their side, while Accelerator protects his loved ones through violent methods and even admits that he is unable to stand by Last Order and Yomikawa Aiho's side. Deep down, he is someone that aches for the light, as shown when Yomikawa Aiho was able to walk up to him and slowly take a gun from his hands before he tried to finish off Kakine Teitoku after their fight, and later when he refused to hurt a Misaka Worst clone and tried to heal her wounds after she tried to kill herself. His obsession with heroes and villains is excised after his defeat in his second fight with Kamijou Touma, telling him to reject the confines of heroes and villains and just do whatever he needs to protect those he cares for.

Aiwass has also commented on the differences between Touma and Accelerator – stating how Accelerator craves for the wholesomeness of being a 'hero' like Touma, even to the point that he declared himself evil because he believes he cannot reach that level. He is someone that tries hard to redeem himself.

Accelerator was shown to often arrogantly underestimate his enemies earlier in the series, which led to his loss against Touma. However, after nearly being killed by Kihara Amata and fighting Komaba Ritoku, he no longer underestimates his enemies. This fact is noted by one of the terrorists in Hula Hoop in Volume 19 as possibly being the most terrifying thing about him: he always uses exactly how much force he needs to in order to defeat his enemy: no more and no less. If he ever underestimated his enemies, it would have given them an opening they could have exploited, but since he didn't, he simply wiped them out with manic glee.

In Volume 22’s afterword the author states that what Accelerator wants most is not a lover but a family, and states Last Order is like his child he has to take care of. Also in Volume 22, Misaka Worst said half-jokingly she wants the same fatherly treatment he gives to the other Misaka clones.

He has a rather lazy personality, showing indifference to people and the events that surround him most of the time. He has a vulgar and threatening way of speaking with easy fits of anger, but he is also capable of showing himself to be moderate and rational if the circumstances are serious.

Misaka Worst stated that Accelerator is a tsundere while she made a brief comparison between him and Misaka Mikoto. For this reason, he rarely shows emotions of affection and concern for others, hiding most of the time behind a mask of hostility and indifference in order not to seem weak. Despite this, the people he helped managed to see beyond that mask, showing gratitude and respect for him, and even admiration from Esther Rosenthal who wanted to be her student.

Last Order
After the Level Six Shift experiment ended, Last Order approached Accelerator to ask him for help. Although reluctant at first, Accelerator eventually decided to protect Last Order with his life. It has been stated that Accelerator is a parental figure for Last Order, and their interactions are like that of father and daughter. Near the end of World War III Accelerator admitted that he always wanted to be with her, as he wants to protect his family.

Misaka Worst
After defeating Worst in volume 20, Accelerator asks her for her help to protect Last Order, and after the war she moves into Yomikawa Aiho's apartment with him and Last Order. Accelerator views Worst as mostly a nuisance, finding her very annoying. Despite this he does not hesitate to rely on her for help whenever they are in a dangerous situation.

The Sisters
"It’ll be all right. If you need something to prove you existed, I will be that remnant. I will dig deeply into this world to leave behind an indelible mark that will prove that you were here as the ones who were sacrificed to the monster that I am. These twisted records are no longer needed. I just have to return you to a place where the dark side of science like me can’t reach you. I will end it all!!"

- Accelerator's conviction before facing Kakine Teitoku During the Level Six Shift experiments, Accelerator was openly cruel and sadistic towards the Sister Clones. He constantly berated every Sister with taunts before and during their battles as well as formulating brutal and horrifying methods against them. However, Last Order theorizes that his actions were intended to scare the Misaka Sisters and demoralize them from continuing the experiments, thus implying that he never wanted to hurt them, but Accelerator dismisses her theory.

After his reform, Accelerator expresses remorse for the atrocities that he has committed and devotes himself to protecting the lives of the Sisters. The guilt on his conscience was substantial enough to push him to an emotional breakdown in his confrontation with Misaka Worst, stating that he would never bring pain or fear upon the Sisters again.

The Will of the Whole Misaka Network states that the difference between him and Touma is that he views The Sisters as the epitome of good while Touma views them as normal humans.

Kamijou Touma
After Touma defeated him, ending the Level Six Shift Experiment, Accelerator hated Touma with a passion. Just the sight of him was enough to send him into rage, such as when he saw him during the events of SS1. He also subconsciously admired him and was jealous of his heroic personality. Aiwass says that Accelerator is "chasing after" Touma and wants to be like him. After World War III, Accelerator has calmed down about Touma and befriended him, fighting alongside him in the invasion of Hawaii and trusting him enough to lend his powers to his ideas. During the Agitate Halation Project, Accelerator even goes as far as to say to Touma: "Do you know what you need to do?" and when Touma replied: "Yes." Accelerator declared: "Then go. I’m not the protagonist here." Touma replies: "These ‘heroes’ are being controlled by a project called Agitate Halation. Be careful." Accelerator finishes the conversation by saying: "Who do you think you’re talking to?" Here, it appears as if Accelerator has already managed to become confident in regards to his strength in relation to Touma's. However, Accelerator also acknowledges that he will never be quite like Touma and therefore lets Touma take the spotlight.

During NT10 it is shown that Accelerator now cares about Touma to the point that he lost to him on purpose so that Academy City and the other level 5 espers won't come after him, since defeating the strongest one of them would mean that it would be impossible for the weaker level fives to win.

Hamazura Shiage
Because he killed the first leader of Skill Out, Komaba Ritoku, Hamazura Shiage was originally hostile to Accelerator. When he was escaping with Takitsubo Rikou, which was when Accelerator first met Shiage face to face, Shiage had mistakenly thought that Aleister Crowley had sent Accelerator to kill him. Because of this, Shiage attacked Accelerator but failed to defeat him, and the fight ended after Accelerator was able to clear up the misunderstanding. After World War III, both Hamazura Shiage and Accelerator returned to Academy City and later worked together to save Fremea Seivelun. When both had met Kamijou Touma, the two were introduced to the magic side of the world and were told of the existence of GREMLIN.

Yomikawa Aiho
After he saved Last Order and was crippled, the researcher Yoshikawa Kikyou took both Last Order and Accelerator to Aiho, where they lived with her as freeloaders. It is stated that she is one of the few people which Accelerator sees as his family. In Vol. 15 he used his Black Wings to protect her because Kakine had hurt her badly and was about to kill her. After his fight in Russia he, Last Order and Misaka Worst are living now together with Yoshikawa, one of the few examples of their close relationship could be seen in NT 1, where she punched Accelerator after he came back from WW3 and hugged him tightly directly after. She is one of the few people to treat him like a normal boy and at the same time she treats him like a child. Their bond is very similar to that of a mother with her child.