X-Men fall out
This is a three-way battle between the three teams of X-Men, with the mansion serving as the battleground. All three teams begin in opposite wings of the mansion, with no prep.
Astonishing X-Men
1. Cyclops
2. Beast
3. White Queen
4. Kitty Pryde
5. Colossus
Uncanny X-Men
1. Storm
2. Rachel Grey
3. Bishop
4. Nightcrawler
5. Wolverine
The ADJECTIVELESS X-Men
1. Havok
2. Iceman
3. Polaris
4. Gambit
5. Rogue
OK, I'm thinking.... Astonishing takes it. Without much difficulty, either. They've got the strongest psychic on the team, and Kitty Pryde can take out most of the X-Men pretty easily. And of course, they have Colossus.