Well normally it takes two gjallarhorn shots for crota normal for him to kneel 2 gjallarhorn shots = 1 nighthawk shot [b]OP[/b] now hard mode takes 3 gjallarhorn shots so roughly 1 nighthawk shot and possible one hunger of crota shot should do more then the trick or one gjallarhorn rocket [b][u]worked out as a level 32 results may vary as a Lvl 33/34[/u][/b] [b][i]for best results recommend Lvl 34[/i][/b]