A word of warning: I've tried Koralon on the PTR, and we one-shot him. He is currently easier than Archavon in terms of execution, and much easier than Emalon in terms of DPS benchmarks. We were all in very good gear for our level. Your mileage may vary.
Koralon has no adds. The fight can be single-tanked on 10-man, or at least we did it that way. Here's a breakdown of his abilities:
- Lava Burst: A straightforward DD spell used against the main tank.
- Burning Cinder: Koralon tosses fire onto the ground. It does periodic damage to those standing in or near it.
- Meteor Fists: Like any other Meteor spell, this punch will distribute and split its damage equally between those standing in front of Koralon.
- Burning Breath: An uninterruptable spinning breath that deals damage to everyone in the raid.
The strategy is somewhat along the lines of:
I jest, but that's pretty much the fight. All you need to do is not stand in fire, get healed through the paltry damage for which Burning Breath hits you (and not very often), and (if the tank needs it) bunch up at Koralon's feet before Meteor Fists.
I fully expect him to get buffed before he goes live, along the lines of other very undertuned bosses that got a boost before hitting the live game (Hodir, Ignis, etc).
Patch 3.2 will bring about a new 5, 10, and 25 man instance to WoW, and usher in a new 40-man battleground called the Isle of Conquest. WoW.com will have you covered every step of the way, from extensive PTR coverage through the official live release. Check out WoW.com's Guide to Patch 3.2 for all the latest!