As far as AAing Hotaru goes, there's two ways to do it. The first is to use a move whose hurtbox is low enough that it dodges the actual move, and has long active frames, like Nu's 2C. That way you dodge the move and the move lasts long enough to beat Hotaru's invincibility. The other is to use an AA like Ragna's 6A late enough that you catch Hotaru through the back end of the invincibility and hit them out of the recovery. If you do it too early you'll either get CH or both moves will whiff. Of course, if the Hakumen expects you to do an AA, which isn't exactly unheard of, then they can delay their Hotaru too.