Strategy
At the start of this event Midnight will be alone. When her health drops to 95% her master, Attumen spawns right by her. When either reach 25% health, Attumen mounts midnight and gains BC.
Preperation:
1. Assign MT to Midnight
2. Assign MT to Attumen - should be a warrior for disarming
3. Quickly clear trash mobs in this order:
Spectral Stable Hands (they heal

)
CC with Freeze traps and Shackles
4. Keep pulling, as long as we have 2 healers & tanks are fully healed we are good

This is a 3 phase fight
Phase 1 (P1):Brief tank-and-spank.
Continues until Midnight reaches 95%.
Starts when we attack her.
She calls any respawned undead horse trash to help her.
Initiates basic heavy melee attack
DPS MUST NOT PULL AGGRO OFF MIDNIGHT TANK!!!
DPS use light damage output attacks once Midnight tank has built up threat.
Attumen tank can use Midnight to build rage with "white damage"
OR Attumen tank can be on adds that Midnight calls for assistance.
Adds must be clear before P2
Phase 2 (P2):Midnight @ 95% health... Hello Attumen
He immediately uses SC and IP
Main Danger 
= healer pulls aggro before Attumen MT establishes threat. If healer dies...RUN OUT OF THE STABLES
Then run back in, re-buff and restart fight before respawns start.
To Avoid this: When Attumen spawns...STOP HEALING

(that means me...can't handle having injured party members

) until MT has threat.
MT use Bloodrage, Thunderclap, Demorolising Shout or Consecration.
Hunters use MD to help (cast during P1 when Midnight on 94%)
Once you have him MT... move him a little way from Midnight.
Face him away from raid so you are the only one hit by SC.
Warriors Disarm him & use spell reflection to bounce the curse onto him.
Mages and druids remove curse from MT and any non-tanks. This will ensure threat gen and disarms land!
DPS - Simple...hit Midnight BUT not too hard as to pull aggro. (I make you this promise...you are on your own if you have stolen aggro and are low on health...mana will not let the healers keep you alive - either that or bring LOADS of bandages and Health Pots

)
Try get them to 25% health at the same time to make P3 easier