Great way to part #2 cursed thralls - payroll cosmodrome. Go into tower on way to skywatch. Just past door you opened with ghost in early earth mission you climb a few stairs and there is dark room with acolytes. Kill them all. In back corner is a crying thrall kill it and run back to top stairs/entry door. A few thralls and a knight of Crota spawn along with 5 or so lv6 cursed thralls. Gun down the thralls and knight. If you pop in and out of the room they hide from you. It's pretty easy to get the cursed thralls alone. If you don't get all 5 the first time. Leave the drops on the ground, go run around till the mobs re spawn. Repeat.