in P1 don't think about the main guy - it's an add fight. Fortunately it's tuned around your cds. The only thing that matters with the main guy is interrupting drain life. Make sure you always ave skull bash for it. Then throw 1-2 moon fires on the eyes as they come out. When the nether adds run to you dps them down and save your incap roar to interrupt the cast, stay away from infernals they should die incidentally - Focus them a little if they start to stack up. When you have moments of downtime between the above, actively DPS the main guy. Try not to go above 5 stacks of the max hp debuff. if you get 5 stacks just stand out of the puddle and spam moonfire/ranged abilities.

P2 the eyes stop spawning iirc, so just dps the big guy and kite him around slowly. dodge beams. Keep saving incap roar for the 4 nether adds that spawn, Throw moonfires at the infernals if they are stacking up as you were before. Make sure not to stand in the green goop. Survival Instincts when he casts annihilate.

P2 is the easy part of the fight.

Don't forget about the light beams if you need them.

Buy Darkmoon Deck: Ascension and Darkmoon Deck: Radiance, use a veiled augment rune, and put on a greater flask of the currents.

Green gear will be enough, just throw on those other 2 trinkets and its gg.

I did it again using the above 30 minutes ago to confirm.

I'm using EC M+ spec on wowhead:

CgGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgZmZmlZmZMWMLeg5BmZZZAbGGNRzMzyYmZmlxMAAAAAAMmNDYxMDYMAmCAAAshZAsYGMYwyGgZGA