I see a few mentions of this, kinda. So I'll reiterate. First, [i][b]you don't need to be in the strike area to get the kills.[/b][/i] All you need to do is kill enemies in "instanced" or areas that were "darkness zones" during missions. The hangar between the steppes and the divide for example. You'll know you're in the right place when the enemies are level 30. When you go down to the nightfall, just head to any of those other mission areas and kill the level 30 enemies. It works with any nightfall on any planet. If you run out of enemies, just go to orbit and come down again. If you do happen to die (when you don't want to) you won't be kicked to orbit. That made the quest take a little longer than the first time I did it (Phogoth), but it was very easy.