I'm on the PC version and need the this:
It's Only The Beginning 15 
Won an online Disintegration match in the Game Grid. Two or more human players required.
I already have the team one and Power Monger as that's the only mode I can find anyone in! No one plays Deathmatch it seems, I only need one person to trade it
Message me on LIVE: Preykousis
EDIT: I managed to get the Deathmatch one legit after finally finding a game