Well, the one thing I want to say that is Mythic Nythendra is probably the worst fight in EN for shadowpriests. If you get unlucky with rots, your S2M will get screwed.
The one thing I've noticed is that shadowpriest damage is heavily tied to raid damage, especially considering most of our damage comes at execute range. If your guild is having trouble getting Nythendra down to execute range, that's not so much on you as it is the rest of the raid. If your parses on farm content are low, then we'll need logs to help further.
Not going to write a book but start with learning how to use surrender properly. In the example linked you pop surrender, go into void form and then use PI immediately. PI is what you should pop at 70 to 85 stacks to keep you alive when you think you're going to flop. Good StM revolves around getting as many stacks as possible because of its interaction with mass hysteria (you do the bulk of your damage later). If you make one change, do this.
Apart from that, start tracking dot's better. (weak auras are great for this as well as name plates that clearly show them) For example, on ursoc your SW:P uptime was only 90%. https://www.warcraftlogs.com/reports...done&source=60
Thats not really good enough.
Last edited by Deja Thoris; 2016-10-27 at 09:12 AM.