You were a civilian during a fight with a villain and you are watching as the pro heros fights against all of them and are loosing and you see your favourite pro hero (present mic) in a situation where if he can’t get out of he will be badly injured so you decide to do the one thing you know how to do. You use your quirk which makes your voice high and able to duplicate anyone you want (and the copy of the person is healthy and damaged by stress or over the use of quirk) which makes there quirks double so everyone has an extra replica of themselves but it only works by you singing on a high level.