Deadpool is hired to take out a list of characters in a specific order. He is recharged after every fight. He gets all his usual weapons and his teleporter belt thingy. He gets a day of prep before he goes on the tournament.
1. Aunt may (They fight in Queens NY)
2. Jubilee (X-mansion)
3. Cyclops without powers (X-jet hanger)
4. Nightwing (Bludhaven rooftop)
5. Bullseye ( Kingpins office)
6. Batman (Gotham Skyscraper)
7. Captain america (Avengers mansion Lawn)
8. Agent X ( Agent X's fairground place thingy)
9. Ultimate captain america (Triskellion)
10. Psylocke (X-mansion grounds)
11. Dr Doom (Doom's castle)
Ult. Cap probably stops him. Yes, I know he can't die, but Ult. Cap is hardcore as hell and could definitely KO Deadpool. No one else before that can take him down.
Now, if he does manage to defeat Ult. Cap, then Psylocke DEFINITELY takes him down effortlessly.