It is, but at least in Prismatica some people from our world managed to unlock other people's aura. It did drain the person out of all their chroma, but it was still possible to do.

[Sun wonders if it is possible here, too, if the person whose aura unlocks would just instantly turn into a stone statue.

Probably.]

I'm not sure if I would be able to do that though. I've never tried.