aolistia:

When Shouto missed his brother, he would look at the sea. His thoughts about his father, the physical pain he was feeling at that moment – they were all suddenly gone. Somehow, the sea eased his mind. And then before he knew it, he was searching for something, and then he was hoping. Hoping that a familiar figure would show up, the person he missed so dearly.

Being alone wasn’t what hurt him most.
Dabi leaving him was.