There is no worm for Revelations. You have to have the Summing Key and all four worms between everybody in your game, not just you personally. I don't know if the wisp step is connected to the rk5 and xp or not. What system are you on?
Personal preference: 1 from the corruption engine area in DE 1 from the corruption engine area in Mob 1 from the jump pad to Mob from Veruckt 2 from Nacht (the area upstairs where you get the bone from. If you face the the rock/bone, there's one to the right and one to the left near the bottom left corner of the floating rock.) Might not be the absolute fastest way, but it feels like the fastest way for me to do it.