Scheherazade : Special Investigation
This is the final campaign-required recruitment. Best for last.
Hit the aptly placed marker to start this tale of a Middle Eastern ninja.
Your first mission is to take out an ice barrage cannon. These remain huge, easy targets, but keep an eye out for sniper perches nearby.
With the machine destroyed, you'll get a task to bust up some miscellaneous LEGION equipment. This is, if anything, even easier than the ice barrage machine, just follow the marker and shoot the indicated, incredibly fragile pylons.
Shooting the last pylon completes the mission.