Coven of Shivarra was bidding to become our fight with the most wipes so far in this expansion. We finally got it down this week, only a few wipes short of our Heroic Avatar count.
Heroic Coven is an interesting fight in that the individual mechanics are not very hard, but dealing with the combinations can be very difficult. Some mechanics push you to spread out, some mechanics push you to collapse, and there's some randomness as to which mechanics happen when which makes it hard to learn the fight. You may see a certain combo only a few times a night.
For us, our big change was how we handled the marching adds. We switched to a strategy where we tried to lock down all the marching adds. This delays running behind them as long as possible, and makes it a lot easier to find safe spots during darkness.
It took us a little bit of practice, including several attempts where we got fairly close. But something always happened in the last 20% and the attempt fell apart. The final kill was fairly smooth. Hopefully we will be able to repeat this next week.
This is the one fight this tier that has really tested my mana. I was running on fumes for much of the last bit of the fight.
The only other thing to note is that the Legendary Prydaz makes a large difference this fight. It's well worth bringing it out for this fight if you have it.