Bakugou is strong.
If Deku was the embodiment of peace, then he was of victory. He held his head high and walked with confidence in everything he did. And so people approached him, whether it would be from admiration or from jealousy. And Deku was one of them. Bakugou didn't mind, at first. He hung out with Deku all the time when he was younger, due to their love for heroes. He woke up each day, even when he didn't want to, even when he was greeted with screams and pitying looks, and he ran off to accomplish adventures and quests with Deku. So when did he start seeing himself in the weak Deku? He knows even if he wants to deny it. It was when he couldn't handle himself without breaking into tears as the beatings got worse and his cries for help were being ignored.
But Bakugou is strong.
He can go through all of it, even if he has to take it out on someone. But that someone had to be Deku. Oh it had to be oh so weak Deku. Why? Because, in front of him wasn't Deku, his childhood friend who admired him, no it was an exact copy of what Bakugou couldn't be. Weak. He couldn't be weak. He couldn't cry when he wanted to, whenever he wanted to. He couldn't smile when things went his way or when he saw something he liked. He couldn't receive love from his mother. He couldn't be Deku, and yet Bakugou saw himself in Deku. Saw the weak him that he didn't want to exist, in Deku. And so he would beat the boy. He would insult and hit him, just like his mother was hitting Bakugou. But it got to the point where he told him to "go take a swan dive off the roof", it got to the point where he no longer saw that green fluffy hair, no longer saw those green eyes that sparkled. No, he only saw the ash blonde that reminded him of his mother, he only saw those crimson eyes that were supposed to hold sunsets, he saw the bruising his mother gave him, he only saw himself. And so he told himself to go die.
But that didn't happen, because Bakugou is strong.
And so he continued with life and became even stronger. He trained and trained so he could become number one. He trained even harder after the sludge villain attacked him. He trained harder after the sludge villain stopped his breathing for a good 10 minutes as he struggled. Trained harder when he saw Deku run to save him even though he was weak. Harder when he saw All Might recognize Deku for trying even though he was quirkless, even though Bakugou fought harder. Trained until he was the strongest and got into U.A.
And so Bakugou is strong.
He became the strongest, and yet the hitting didn't stop. He became a small child when in front of his mother and so he came to trust no one. He was alone until he went to U.A. There, he met people as strong as him. There he met Deku again. He saw Deku become strong. Saw him fight even though he was breaking bones and now, he couldn't see himself anymore, but he refused to admit it. So he went to class with hate directed towards Deku and the extras in his class seethed at him for it. Seethed at how he refused for anyone to touch him, to talk to him, at how he was so confident even though they trained harder than him, that he so had this "talent" and was stronger. But some people didn't care and approached him. Kirishima did even though Bakugou pushed him as far away as he could. Kirishima kept coming back, just like Deku. They both did. Neither gave up and soon Kirishima's friends did as well. Mina, Sero and Kaminari all did and Bakugou hated it. How could he believe in them if he didn't even in himself? But they didn't care and ignored his every insult. He gave up in the end and continued to train. He proved he was strong when those villains attacked USJ and he did everything in his power to stop them.
Bakugou is strong, so why did they do that to him?
Why did they chain him up when he refused a medal because he wasn't his strongest during that fight? Why did they muzzle him on live television? Why did All Might not do anything? Was it because he wasn't human? Because he was a wild animal? Bullshit, but they still did it. They did it to a child. Why were adults always like this? Even though he screamed and screamed in fear, in pain, all they heard were the roars of an untamed beast. And it was all on national television. Everyone saw him as a wild animal. Everyone saw him as "a monster". After that, he knew about the whispers and stares, but he didn't care about them, even if they did hurt a bit. It was fine that only Best Jeanist knew that he wasn't a beast. That the Sports Festival was a total mess up on U.A's part, but it was fine.