I hope it is not a 'mutant' prison unless it is one specifically designed for Xavier. It should be build to contain any of the big trouble makers who...
For me it's Beast at the moment, because Moira's Krakoa story has a little more to go and I think somewhat of a redemption is on the horizon. Beast's...
She is the easiest to fix and the one who actually had the least done to. Karima was simply 'possessed' and all it takes is purging/reverting the OS...