Horridon himself puts out fairly spiky damage on the tanks at first, hitting them with a stacking debuff that increases damage taken from his primary attack, Triple Puncture. Horridon also does a Double Swipe, shows pretty clearly by a red ring as well as two conical areas in front and behind him. He will periodically charge random members and then immediately Double Swipe, so keep a watchful eye on his position and target.
The adds initially come out of the doors at the side of the arena, currently the doors and adds are a bit mixed up, but as soon as the first set, the Farraki, begin to appear, the tanks should swap on Horridon and the new off-tank needs to pick up the adds. From a healing perspective, the Farraki's Blazing Sunlight is an additional concern, the effect stacks and seemed to chain to nearby players, as well as dealing heavy damage, so dispels were a priority.
Apart from that, as long as people stayed out of sand traps, the adds did go down eventually, leaving the way clear for the next wave of adds, from the next door around. First, though, a Dinomancer will appear, the awesomeness of their name somewhat compromised by the urgency of dealing with them, particularly their Dino-Mending beam which needs to be interrupted. These pop up after each set of adds, and upon their transformation into dinosaurs, drop an orb which needs to be clicked to have Horridon destroy a door. This gives him both a headache, and a cracked shell, poor thing. The latter means that he will be taking 200% increased damage after the fourth wave of adds.
Each set of adds comes with its own special ability, from a healing perspective the stacking DoT effects like the aforementioned Blazing Sunlight, the Gurubashi's Venom Bolt Volley and the Drakkari's Deadly Plague were the biggest issues, as long as nobody stood in the bad areas of the floor. The bad areas on the floor also move around, so this can be trickier than you think. Bringing a variety of dispels would be a great move on this boss, and raid members dispelling themselves and others will be useful.
Lastly, after four sets of adds and several Dinomancers, War-God Jalak will appear. You'll need to have been DPSing down Horridon in the meantime, the trigger for Jalak is either Horridon hitting 30%, or all four add sets having been and gone. Tactics are unclear at that point, as, so far, nobody has killed this boss. Jalak's death causes Horridon to gain a buff called Rampage, implying that Horridon should be killed first, especially as he's taking 200% increased damage, but Jalak has a tiresome ability which damages the entire raid. It's a burn phase, and the best method is unclear.
Overall, the fight currently seems rather overtuned for the second boss of a 10-man normal mode dungeon. Damage on tanks was not overly problematic, nor was Horridon's damage, which actually seemed low, considering he is, after all, the boss. But, the raid damage put out by the adds and their various DoTs and AoEs was rather troublesome to heal through and rather unforgiving. Tanks also had to work very hard to collect the adds, given their number, and they would often escape and pick on nearby healers, making our job all the more tricky. The first set of adds seemed the hardest to deal with, partly because of the sheer number of ever-expanding Sand Traps, but keeping the group mobile seemed to help, as did dispelling the DoT as priority.
It's currently a very hectic, but very fun boss to heal, with co-operation needed between healers and good raid co-ordination to avoid all the damage. We were two tanks, two healers and six DPS.
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