Dabi was your older brother, Touya. You and Touya were twins, your father Endeavour tried to train you both but you two were opposites. He was resistant to the cold but had a fire quirk and you were resistant to the heat but had an ice quirk.

You were a regular citizen who often trained your younger brother Shoto. One day you and Shoto were walking down the streets before you noticed dabi. Dabi recognized you

“Well, long time no see sister!” He had a sadistic grin on his face