So there's been a lot of talk about Accelerator's morality in the episode discussion of Railgun thread. I really wanted to say something but since I literally just got banned for talking off topic and in spoilers in that thread I decided to just write my explanation for his actions here. So if anybody doesn't understand Accelerator's actions and wants to, read this.
Spoiler for Accelerator's Reasoning Behind Participating in the Sisters Experiment:
We don’t know much about Accelerator’s past before he started being called Accelerator other than that he considered himself a normal kid. It’s possible that he was a child error considering his parents have never been mentioned, but who knows. The important thing is that he lived a completely normal life just like any other kid. Then the incident happened.
It started with some kids his age who rushed at him having their bones fractured. Then the teachers who tried to stop him, and finally Judgment and Anti-Skill. He utterly defeated all of them without even trying. Try to imagine how horrifying that would be for a normal kid, to not only having everybody you look up to (his teachers) but also the people supposed to protect him (Anti-skill and Judgment) call you a monster and try to brutally kill you. And then having to watch them get ripped to shreds in front of you from their own attacks. It would have been unimaginably traumatic.
Accelerator’s response to this incident was to push all his feelings down because he realized that if he got angry he would start to kill people, and “This commotion would snowball until he ended up fighting against Academy City, the world, and then everything would be destroyed.” (from the LNs). The downside of this however was that he just stopped caring about anything, including whether the people he had been trying to protect died.
So, since he had just stopped caring he surrendered and let Academy City start experimenting on him. We don’t know exactly what happened in the facilities that he went to but we all know just how horrible and cruel Academy City can be in the name of science. So I can only imagine it involved a lot of pain, loss of human dignity, and a ton of isolation. For years, while he was a child.
Eventually he got out, I’m not sure if this was when Yomikawa’s unit dismantled the facility or before that but it happened. Only when he got out he couldn’t live a peaceful life like a normal person. Everywhere he turned people started to attack him in a doomed attempt to prove that they were the strongest. And he effortlessly destroyed all of them without even having to try.
Then the scientists came and started trying to convince him to join the experiment. They told him that people were only attacking him because he was only “the strongest” and that all he had to do was become so strong that nobody would even think of attacking him. Think of it as Accelerator was the biggest kid in a really rough high school in a really rough neighbourhood, so everybody kept attacking him so that others would call them the strongest. So he wanted to become a professional boxer, because while the other students might think they just might be able to beat up the guy everybody called the strongest in the school they wouldn’t even think they could take a professional boxer on. He would finally be left alone.
Then they told him that all he had to do was kill a bunch of lifeless dolls and then it would be over. Now you and me could easily see the moral problem here and say no but imagine how this sounded to a half-crazy from abuse child who just wanted so badly to not have to hurt anybody anymore.
And while consciously he accepted it his subconscious mind wasn’t so sure. That’s why before every fight he talked to the sisters. That’s why he taunted them and hurt them so badly. He wanted to see if they would give some sort of reaction that would mean they were not willing to go through with the experiment any more. He was subconsciously offering them a way out every fight, and all they had to do was take it. Which none of them did, simply because they were incapable of understanding his intentions and of seeing themselves as anything more than lab rats that were to be disposed of.
Now it’s important to note that none of this excuses Accelerator’s actions, hell even he in his wildest fantasies doesn’t believe he can ever truly redeem himself or be forgiven for the horrible horrible things he did. He was still very much in the wrong to kill those sisters. However it does let us understand him and not judge him too harshly, and allows us to understand why he ultimately decided to start protecting Last Order and start on his path to being a good guy. Even if he refuses to admit that’s what he’s doing.
If made any mistakes there please let me know.