Did everyone really act like nothing happened? Not really... Forgiven doesn't mean they forgot what he did... They simply realized he wanted to be better and was acting like he wanted to own up to his mistakes.
Saying they are all acting like nothing had happened is literally diminishing the hardwork the Todoroki family has done to just accept him a bit...
They all moved forward, realizing they couldn't cling to the past as it would just torture them forever..
Everyone moved on besides Dabi.. Who is still stuck in the past which is why he is the villain.
He was abused but so was Shoto.. They all suffered immensely, the only difference is everyone thought he was dead and moved on with their lives Meanwhile he couldn't, he couldn't forgive nor forget and started to hate the whole lineage even if they were also victims..
Endeavor had to go through a lot to make his kids forgive and they did, they are working on it. Dabi coming in like this to to literally throw them back into the past they all wanted to move from and force them to relive it again, it's cruel...
Dabi looks like a burned Bakugou now with his light hair. I'm laughing at everyone who forgave Endevour and said he changed and is good now. Yes he may have changed. But what he did to Dabi is mental and physical torture yet everyone acts like it never happened. NOW THERE YOU GO! Endevour deserves a punishment for his child abuse.