Vidmaster Challenge C Achievement
Vidmaster Challenge C10
Complete Operation C, Mission 6 with the Black Eye and Pacifist Skulls active
For this mission I'd recommend using the Overshield Armor Ability and buying the Damage Boost upgrade. You'll only want to be melee killing enemies, but you can also use grenades. Save your grenades for Knights, especially ones with Scattershots. Otherwise regular Knights and Elites are two hit kills, and everything else is a one hit kill. While running to the bottom of the map to hijack the Covenant ship, just melee everything in sight while running through as fast as possible. You can skip the Chieftains by running by them.
Use the Overshield ability when your shields are really low; you'll be invincible for 8 seconds. You should have any trouble if you follow this guide.