Jaraxxus is the second boss in the coliseum. When you speak to the guy at the entrance again you will....hmm...wait, lets not spoil this.
But you end up fighting a big red demon called Jaraxxus. If you want the full overview, go here, Matticus did a darn good job describing all the abilities. I will just call out what you need to watch for in the fight, and give you the clear cut answers.
- 2 tanks
- 3 healers
- 5 dps
- 3 tanks
- 7 healers
- 15 dps
Yes, many healers, it's a very healing intensive fight.
He has many abilities, and most of them you have to counter in a specific way. It's a trick fight, and when you know the tricks you'll do fine.
- Fel fireball - Have someone assigned to interupt this, preferably a dps. It abosulutely has to be interupted. If it's not interupted it leaves a dot on the person who it has hit which can be dispelled, but if you burden your healers with this on top of everything else you're not going to have happy healers, so just make sure to interupt.
- Incinerate Flesh - Heal, heal, and heal more. You have to heal a certain amount (depending on instance version) within 15 seconds on the person who has this to make it go away, or you will likely have a wipe on your hands. The person who had it will still take damage after the debuff is removed so keep healing.
- Legion Flame - Whoever gets legion flame should run to the outside wooden ring and run it off around the ring. I say to the outside so you're out of the way of others, and running because the fire will follow you for 6 seconds.
- Nether Power - This is a buff on him, dispel or spellsteal it. If you do not, he does more damage.
- All the rest can just be healed through. There are other abilities that can be interupted, but they are less critical than what is described above.
- Infernals: only ranged should kill them. They have an aoe pulse every time they stand still.
- Mistress of Pain: all dps can kill her.