Midoriya's older twin sister was born with two quirks, the theory is that she took his when they were really young it was her responsibility to protect him...... and also fuck the guy that bullied him, soooo yeah just read the story (i will explain her quirk in the first chapter) (if you are quirkless your quirk is still written in your DNA and her quirk allows her to copy that DNA and use the quirk that they can't use)