Well, I just got all three psion flayer cloaks (Destiny)

by Speedracer513 , Dallas, Texas, Friday, October 23, 2015, 18:36 (3414 days ago) @ Kahzgul

How many strikes did it take you to get them all? Did you run Nightfalls or another playlist?

Based on what I've heard and seen from people, you can get the cloak(s) whether you launch the strike from the director or get it in a playlist, but it seems that the drop rates are much higher in the higher difficulty playlists...