Sorry for the wait!
I really like the plot. It's very original, and I can see a lot of ways this could go. However, I would remove the bit about allowing them to have supernatural powers. This roleplay has gritty, harsh realism, and I think that aspect would ruin it. I can imagine humans going insane in the building, but not X-men. =P
The description and detail (which there is a perfect amount of) bring about a very creepy, horrible, and claustrophobic aura, which, I believe, was your intention.
As for the character profiles, it follows the theme, which is good. I would remove the bit about the personality, as that should be something that is revealed in the roleplay.
The name works, but it could be better. =)
Hope that helped. Sorry again for the wait and the effort for you to get us to read. sweatdrop
...so fricken' awesome. ::.