In Mass Effect 3 for the PC, PS3, and Xbox 360, you can unlock the Asari Adept as a character to use in multiplayer, which is a fast and agile biotics pro.
The Asari Adept is a rare card that you can get from purchasing any of the packs, however your chances are quite a bit better to get characters by purchasing Veteran and Spectre packs instead of Recruit packs.
Check out my other guide for more unlockable characters in Mass Effect 3 multiplayer.