wow, that's a pretty cool support quirk!
my OC Itazura's quirk is based of FnF, she sings, she creates arrows, she launches the arrows at her enemies. And he special move lasts for about 3 minutes (depending on the of song length), where if she concentrates long enough, she can sort of copy an existing FnF's character's moveset (though in MHA it's basically an OC to her), within reason though, so no shaggy or stuff like that. Also there's a cooldown of at least 2 hours in between each special move(e.g: she could copy a ruv sort to amplify her voice to earthquake-creating loud for about the length of zavodila, but then will have to rest for 3 hours later before she can use her special move again)
yes I've had her for a while so she's been bonked with stop-being-so-op-im-giving-you-a-debuff stick