Dabi is a cold merciless villain who only serves under shigaraki to ruin enji or his father's life to get revenge for abusing and neglecting him for making him create his ambitions just to break it to pieces his work is only for his hatred on his own father. He would also judge others according to their appearance since his face was made like an angel and he knows but his burns conceals his beauty so he'd get a little insecure about it

Dabi meeting a siren 

Tomura Shigaraki a merciless villain

Tomura Shigaraki is a well known and most powerful villain in Japan he is a merciless serial killer for his goal was to change the rotten society he sees as all for one or his master manipulated him to think so, to create him as a successor for his quirk and use him against the successor of one for all; izuku midoriya to finally be able to get the most powerful quirk and claim victory 