Control

This is a story achievement and cannot be missed. The only difficult part when it comes to completing the "My Brother's Keeper" mission is defeating Salvador. What I found to be most helpful was a combination of Pierce, Grip, and Seize. Take out some of the weaker enemies using Grip. While you are eliminating the weaker enemies, use Seize to take control (no pun intended) of as many of the enemies as you can. The weaker enemies, once on your side, will help with the other weaker enemies, and they might even take some health off of Salvador. For Salvador himself, use Pierce and the environment for cover between shots. Launch is also helpful during Pierce recharge. Alway keep moving and using the environment strategically. While moving, use either Evade or Shield to protect yourself from Salvador's explosive attacks. I hope this helps!