In Mass Effect 3 for the PC, PS3, and Xbox 360, you can unlock the Turian Sentinel as a character to use in multiplayer, which is a powerful support character that can use both tech and biotics.
The Turian Sentinel is an uncommon card that you can get from purchasing any of the packs. Your chances are typically better to unlock characters by purchasing Veteran and Spectre packs instead of Recruit packs though.
Check out my other guide for more unlockable characters in Mass Effect 3 multiplayer.
