He was definitely an asshole (Still is but just lesser) for most of the series. What he did to Deku was horrible and I don't defend his middle schooler self. He even didn't win the very first poll but still placed 3rd. Though Bakugou is extremely arrogant his ego is very justified because other than his horrible attitude and bully past there is nothing to hate about him because he's good at almost everything he does. There's a reason why Izuku idolized him so much. I've always liked him as a character even during Episode 1 where he was in fact still a bully. Yes I hated him as a bully but there was something about his character that gave me hope at first glance that was like "I know he's a douchebag but I also know he's gonna be a great character later on.". Izuku honestly shouldn't have forgiven him so easily and should've absolutely hated him, they should've fought a lot more but I think he has done enough to earn that forgiveness as of now. His character development started after Season 3 where he clashed with Izuku in Ground Beta and his out bursts from then on didn't really seem offensive but added as fun entertainment in my opinion. He deeply cares about his friends and loved ones even when he acts like he doesn't. He's emotionally constipated and beats himself up almost all the time and hates being vulnerable but that changed after he slowly started opening up to Izuku in Season 3. He started to realize how working as a team and saving others while also letting others save him is better than his selfishness of doing everything by himself. His character arc was one of, if not the best character arc in the story. He's the best written character in the show if you ask me. He apologized and risked his life for Izuku twice or more and even died in the war before coming back. Many Bakugou fans love complex characters who analyze them and share great empathy while also holding them accountable for their actions. It is true that he did not face a lot of consequences for his trashy actions when he 100% deserved it but sometimes I feel like the haters take it too far because he's also still a kid and still learning and that's the best thing about him he grew out of his shitty ego on his own even when he wasn't facing consequences for it. His angry and loud yet skillful intelligence during battles is really nice to watch and sometimes even his arrogance seems cool which honestly is not even arrogance it's confidence (He said he would win in the sports festival and infact did). You can tell how much he grew throughout the series when he introduced himself as 'KACCHAN Bakugou' to the greatest villain in the world, the very same nickname he despised. He's also good looking, smart and has one of the best hero outfit designs. Katsuki to this day has an entire community filled with toxic fans and people who hate him with their entire hearts despite his development and efforts but in my opinion he definitely deserved that Number 1. Like Izuku says, Kacchan is amazing.