I agree with you on Khale, he deserves it the most, Mastermind is kinda iffy, if Mastermind 4 comes out before Comic-con maybe, but right now the series has been hit or miss, I enjoyed them, but alot didn't.
My best suggestion would be the main character from whoever wins the best MGS Collab piece, that is if the winner is declared before you leave. Or even if Disc Two comes out by then.
A few others would be
Fancy Pants Man, and the default character from The Torture Game 2 just for the LOL's.
For my next trick, I will need a condom and a volunteer.