Mass Effect: Renegade Lost

(Mass Effect: Galaxy at War Prequel):
After the corporation that "gave him purpose" turned out to be the cause of all his pain, Subject Seven is ready for revenge. He will stop at nothing to hunt down and slaughter every Cerberus officer responsible for the attack on his colony, the deception, and the experiments done on him. This mercenary has turned the gifts Cerberus gave him against them. This is the story of Lieutenant Sev.