There is an unlockable Battlefield 3 Soldier character for use in multiplayer games in Mass Effect 3 for the PC, PS3, and Xbox 360.
To unlock the Battlefield 3 Soldier in Mass Effect 3, you just need to have purchased the Battlefield 3 Season Pass and link it to the same EA account you use to play Mass Effect 3.
Don’t have Battlefield 3? Well why not? You can buy the PC version here
