I think there’s actually a super complicated way to do it.
You could animate the overlays by creating a bunch of different overlays where the characters slowly move, if you know what I mean? Like a whole bunch of them. Then make them appear fast to give the illusion that it’s animated. It would be really, really, hard.
You could also put characters over the spotlight bubble overlays and then make the surrounding background an overlay to hide their feet. That would also be difficult.