I had some time to go through the logs today and came up with the following.
Over the last week there have been 774 Mythic Kormrok kills publicly record on Warcraftlogs. The average fight length was 4:42, and only 21 of the kills lasted longer than 5:10 (our last attempt).
Which means we have basically seen the entire fight, all we need to do is clean it up and we win.
Areas to improve:
Hand Kill Speed: We had some good phases but overall our average time spend in the hands was on the high side. From what I saw in the logs I think our biggest problem with the hands is inconsistency. So rather than save big dps cooldowns for the hands, I think we need to focus on saving the right ability cooldowns for them. Some examples, over our attempts my Starfall would do about 800k damage during one hand phase and it would be around 60%+ of my damage to them. Now there was a time or two that I was bad and did not have a charge to use. If I pop'd all my cds and the ring my damage to the hands without starfall would be lower than using starfall and no cds. Another easily seen example is with Uluuru, on the one hand phase that Kull specifically remarked about our speed Uluuru did about
4mil damage with Divine Storm + the extra holy damage from it. Now that time he had a nice proc and was able to use 2 buffed up Divine Storms for the hands, and he did
25% of the total damage to the hands. Compare that with the next attempt where he only did
7% of the hand damage without using Divine Storm. (he used it right before they spawned and probably miss timed it because the "Dragging Hands" ability had finished casting ). In the logs I generally saw most people doing good damage to the hands on some casts and then not having the same things up for others. Which is understandable for the first night on the boss.
Rune Management: Cut's already linked it, but I like the 2 rogue strategy. It doesn't have to be rogues but 2 people with cooldowns run around the circle pushing each rune to the next rune until they meet in the back. This not only allows everyone else to not worry about them, but limits unnecessary movement that can be cause by the runes being pushed to the center around everyone. The 2nd empowered rune phase starts 10sec or so before the boss jumps into the purple pool, depending on how long it takes to soak the runes we might give rune soaks lower priority positions or not have them worry about soaking the last splash.
Damage to boss: We obviously need to bring dps up a bit in order to kill the boss in a timely manner(32% was our best). But I think most of that will come from being more comfortable with the fight and flow of abilities, and having a full raid always helps. Other than maybe changing the way we handle the runes, my only strategy thought for increasing dps is to tank the boss on the edge of cleared area instead of towards the middle. This would make the hands pass through the boss adding additional cleave damage and also allow the tank to stay in one spot when the Explosive Burst is used with most ranged being already far enough away to not get hit.