Just tips you may already know - I'd avoid decrypting for any spot that is at or above your over level. I think you'd have a high chance if you worked on your other armor first before trying your helmet. The artifact isn't going to be easy to raise, so I'd make that the last of the four you need to focus on. Any chance you're close to a level increase on Eris? Think of it this way, don't be too optimistic of getting a gain on your 396 primary when you have other gear at 391. On the opposite end, if all your gear is 385 except for your 350 ghost, don't waste other engrams until you get a good ghost. I'm not excusing this mechanic by giving these suggestions, nor is it my intention to dilute your point with my comment. I've given up raising my light. I don't care to participate in the grind this time around.