WARNING: The following contains spoilers for My Hero Academia #301, by Kohei Horikoshi, Caleb Cook and John Hunt, available now in English from Viz Media.
The Todoroki family drama of My Hero Academia is unique among shonen manga for its deep and complex portrayal of familial abuse. With Shoto's isolated childhood of tear-inducing training, Rei's mental trauma driving her to maim her child, Toya's "death," Natsuo's deep-rooted grudge, Fuyumi's sorrowful longing for a happy family and Endeavor's attempts to atone for his misdeeds, the Todorokis are a multifaceted array of perspectives on the way abuse scars a family.
In Chapter #301, we learn more about the circumstances that twisted Toya into the mass-murdering villain known as Dabi. Tragically, it reveals his self-destructive commitment to the path he now walks -- and the impossibility of his salvation.
Even as a child, it was apparent Toya had inherited more from Endeavor than his powerful fire Quirk. He too became obsessed with surpassing All Might to become the #1 Pro-Hero. Eager to train with his father, Toya wasn't prepared for when his own body began to turn against his wishes. The slow whitening of his hair was the inexorable proof he'd inherited the genes to resist ice, not fire, meaning his own flames badly burned him.
Endeavor and Rei tried dissuading him from using his Quirk, not wanting to see him char his own flesh for his ambitions. But Toya was hell-bent on becoming #1 as his father had once promised he could. Worsening matters, Endeavor still desired to produce an heir capable of surpassing him, and so Natsuo and Shoto were born. Endeavor's intent with this was both to continue his obsession and force Toya to give up on their shared dream -- the stubborn child was coming home with fresh burns every day. But it backfired.
Filled with dark rage, Toya attacked his mother and baby brother with super-heated flames. He saw Shoto as nothing more than an object to destroy to get back at Endeavor for stealing his dreams, rather than a person in his own right. That was the first time Toya tried to murder Shoto; we already know it wasn't the last. In My Hero Academia's recent War Arc, Dabi sought to murder Shoto in front of Endeavor for the same reason as all those years ago: causing the maximum amount of pain to the one who hurt him.
It demonstrates just how badly Dabi is ruled by self-destructive desires. He's had the same murderous super-objective since childhood -- murdering Shoto -- and he lacks any empathy towards the rest of his family or even the League of Villains. He only cared about Twice's death in as much as it was useful to him; he plotted to put Natsuo in the path of the villain Ending and he won't rest until Shoto is dead and his father is utterly broken. The child his family loved is gone. Only his ashes remain, as the vengeance-fueled villain, Dabi.
