Majordomo Executus

Majordomo Executus is the last of the Flamewaker Generals of Ragnaros which needs to be defeated. The boss will not be able to be engaged until the other 8 previous bosses have been defeated and the 7 Runes of Warding have been extinguished by the use of Aqual Quitessence. Majordomo Executus is accompanied by 8 adds, 4 Flamewaker Healers and 4 Flamewaker Elites. Because the encounter involves so many mobs, it is important to have your tanks assigned to the mobs you want to handle first, and utilize off-tanks, CC effects and kiting to handle the other mobs. To succeed in this encounter, you do not need to defeat 'Domo himself but instead need to kill all 8 of the Flamewaker adds.
Overview
Tank
Whoever is tanking Majordomo himself is going to be teleported into the coals in the middle of the room, which deal damage to those standing in them. Move out of the coals and reposition the boss. Off tanks need to be in clear communication with the raid about the kill order and which add needs to be picked up next. Be careful not to break CC effects until you and your healers are ready.
Damage Dealers
Mages are able to use [Polymorph] to CC the Flamewaker Healer adds. So assign Mages to each of the Healer adds that you wish to CC to be sure that their [Polymorph] spells are kept up the entire time. Flamewaker Elites are immune to CC, but can be kited around the platform by a Hunter. Ranged and Melee DPS need to pay careful attention to the kill order, and be sure that they are damaging the correct target at the correct time. Be aware that [Aegis of Ragnaros] and [Magic Reflection] deal damage back to the attacker or caster, so be careful not to kill yourself while these shields are active.
Healers
Assign your healers to your Tanks and Off-Tanks and be sure to always be in range of them. Healers during this fight will need to keep their attention on different members of the raid, as there may be raid damage to all members throughout the fight.