|Donuts to Drones||A Straight Answer|
Buddyguard - Complete mission without more than 10 R-Corp Marauders being active at once. - 1250 Plex.
Big Budder - Defeat more enemies than Skali. - 1250 Plex.
R-Corp Marauders will spawn in waves at the various 7r places around the map. See the picture for exactly where. If you have a fast ship, you can intercept them before they can gang up on you and Skali, and before Skali can reach them.
Skali's location is marked with a waypoint on the map.