In the "The Savior" mission, you need to kill 20 enemy soldiers between the beginning of the mission and completing your final objective. I recommend playing this on easy, because you'll need to get a lot of kills in a short period of time.
The first half of the level are gimme kills, you get five just for playing through it and taking everyone down. It's the second half of the level, when you're outside, that's problematic. Once you make your first kill outside, you have 3.5 minutes to get up to 20 total level kills AND complete all your objectives. Here's how I did it:
- Take out the two guards on the ground immediately in front of you when you start the level.
- Climb up the stairs on that side of the building, and take out anyone in your way.
- Go up the additional set of stairs and grab the sniper rifle from the middle of the platform.
- Come back out through the upstairs vent and take out anybody on the upper platform.
- Go downstairs and shut off the first security system.
- Take out anyone in the lower level round area.
- Go downstairs, and shut off the second security system.
- Go back outside, and clean up anyone left until I hit 20+ kills.
- Finish level.
A few notes:
- Grab a machine gun as early in the level as possible.
- Remember to keep scanning for enemies! (right on the d-pad) If you know where they are, it's much easier to take them down.
- Engineers will be deploying turrets. Do not try to destroy them, just find another route. Your ammo / grenades are best spent elsewhere.
- You have a few grenades, if you ever see any enemies grouped up remember to use them!
Keep count! If you're not at 20, you'll need to reload the checkpoint. Make sure you give yourself ~20-30 seconds at the end to get through the vent and complete the final objective! If you don't complete it, nothing counts and you'll have to reload.