Arknights - DM-6, three ops trust farm: Phantom, Exusiai, Platinum (or any decent ranged)

Phantom is Rank 5, Exusiai is mastery 3, and Platinum is rank 7. Recorded this on my first try with this comp so timings could be a bit better. But it's important to time the Exusiai skill so it's up to help wave clear at the start and then again to kill the boss. Any decent sniper or other ranged operator could be used instead of Platinum.

Phantom E2 L30, Exu E2 L90, Platinum E2 L26. Exu could be way lower level, it doesn't matter as long as the skill is timed right.