Duly noted. Thank you for sharing ^_^*raises hand* I am.
On a basic level I really like his lowkey intensity which can give way to rare moments of him excitedly howling out murderous intent. And as far as edgey bad guy designs go I really like Dabi's. It's kinda subdued compared to others, but the plethora of burned skin and staples is striking to me. It tells you that this guy is used to pain out of necessity rather than desire which makes me interested in how that came about.
Granted, a lot of why I'm so interested is conjecture tied to the mystery of his identity and the possibility of him being Touya Todoroki and all the story potential of that. Which, if true, would just open up a massive can of story worms. Especially for Todoroki. Dabi would be his long lost brother that he has to save, a dangerous serial killer he has to stopp and a physical manifestation of Endeavor's abuse that he'd need to confront all wrapped up into one person.
So in short, I just think Dabi's a cool villain with a lot of story potential brewing within him that hasn't had the chance to erupt yet since he has been focused on as much as some of his companions. But Horikoshi has left plenty of crumbs that entice towards the character and his hidden story.