CyberAngel
You taken so many battle injuries and had so many cybernetic limb replacements you don't even know how much of you is human anymore. You're faster and stronger than any other marine out there but noone can give back your good looks. Oh, and the maintenance is terrible.
You start the game with equipped armor Cybernetic [4/4] 200% +20% speed, -50% knockback. You can't remove this armor and if it gets destroyed you lose the game. In compensation, you can use green, blue, red and unique armors for 10, 20, 40 and 50% armor repair respectively. Good luck.
P.S. - The numbers will need tweaking, so don't take these as final. Increasing the Cybernetic to [6/6] or the armor repair seem like real possibilities. Anyway, stay away from Barons and Acid barrels :P.