Shatter the BastionsG 15

The best way I have found to get these guys is by doing secret missions during free roam on earth. There is one secret in particular you can find requires you to interact with a marker and defend it for an X amount of time, while doing this there will be an increase chance that there will be these enemy types infinitely spawning out of the small portals for the objectives time. They are the ones that look like Human knights. This can be tracked under your “Merits” Tab.