>>101947075
That's Cyana, and she's Puerto Rican. Used to be Maika Mallow but ditched that persona to do a more authentic voice.
She actually does a lot for Nyana and is legit good with... I dunno, vtubery computery stuff. I think Nyana actually gave her a copy of the concert in its entirety for tonight in case her own PC shit itself (i wouldn't take any chances either).