Solo the JLA!!!
Here's the deal...the JLA roster is given below.
In this scenario the memeber of your choise has to kill the rest of the roster in order to save the world. He has 15 minutes before he enter a giant adamantium room with only two doorways.
The others are unnaware of his intentions so he gets the benefit of surprise.
Who has the best chance of doing so?
The roster:
Superman
Wonder Woman
Hal Jordan GL
Firestorm
Captain Atom
Martian Manhunter
Wally West
Maxima
Orion
No CIS, PIS....
make your choise