Traitor Game: Search for the Next Nexus!

Traitor Game: Search for the Next Nexus! by Superheroic
Premise
After learning that a Traitor Game led to him becoming Nexus, Horatio Hellpop had enough. Storming in to confront the insane alien God, the Merk, who imbued him with his incredible fusion-casting powers, Horatio forsakes the mantle and quits being Nexus.
Determined that humanity still requires a Nexus to dispense justice in his name and since this last Nexus worked out so well (up until now that is), the Merk goes back to his old tried and true method of selecting his Judge, Jury, and Executioner of human mass-murderers...
He starts a Traitor Game!
Roles & Rules
Player Characters in this game have been invited to become the new Nexus. The catch is they need to prove they have the right stuff for the job by eliminating their competition. If I can come up with something that works, I may be instituting some new mechanics for this one such as a "Round Robin" or "Last Traitor Standing" style elimination. Basically for this one, I may have the Traitor Roles change between rounds until there is a winner.
Character Requirements
All Player Characters in this game must be Human. No aliens. No demons. No Asgardians, Olympians, Eternals, or New Gods. I'm leaning toward no half-human characters either but am open to allowing them depending upon the character. Characters who were once human may be subject to approval also. Marvel's Mutants are fine as well as "Powered' Humans. However, powered humans that evolved too far beyond humanity, like the High Evolutionary or Doctor Manhattan are not eligible.
All Player Characters must have come willingly to the Traitor Game. After all, they've been invited and are welcome to turn down the invitation if it suits them.
Finally, all Player Characters and must want to become the next Nexus. Whatever the reason, all characters must start the game with the intention of winning and becoming Nexus. After all, the Merk doesn't really care who the next Nexus will be, provided they do a good job.
EDIT: Superheroic has postponed this scenario due to other commitments. With his officially announcing his retirement from the Traitor Games on August 5, 2011, it does not seem likely that this scenario will actually occur.