Topic I need help on horridon
One problem with this is that they only have about three interrupts (1 tank, DPS Shaman, Hunter?). 4 if you count the Holy Paladin, but since healing was apparently not something he was capable of in the fight, I don't think I'd trust him with interrupts, either.
Silence works on the adds (though the 45 second cooldown sucks), so I don't see why Spell Lock wouldn't work. I guess a Warlock could run with a Felhunter for Horridon.
Just want to add my 2 cents here.
There is only so much healers can do on Horridon. You heal and dispel. The key of this fight is how dps handle the adds. The disadvange of 10m Horridon is raid comp, i.e., lack of debuff dispels. On the 4th door, your dps shaman is probably the only one can remove Curse. When you get there, you may need to ask him to do it, and there may also need a dispel priority (e.g., only on tanks).
I also saw a lot of dispels on the 1st door. It took us a while to realize dps needs to prioritize kill orders on first door too, so healers won't be overly burdened by dispels. So besides the Dinomencer, the Farraki Wastewalker should be focused down asap.
For the 3rd door, it would be helpful for healers to be able to see the stacks of Deadly Plague on their UI. Dispel the one with higher stacks first. Certainly, make sure every healer can see the debuffs. For example, my Healbot needs special twicks to show some debuffs.
Disc is so much ahead on this fight. Until you outgear and have this fight on farm, Disc would be a better choice. If your armory is showing your Holy gear, I think it's a little low on Spirit, especially if you need to spend a lot of mana on dispels.
If you are the only Disc priest, make sure you have the Horridon tank in range all the time. I found undergeared or less experienced tanks on this fight tend to have health spikes a lot. Use direct heals, even Flash Heals, on them when they can't be bubbled. Also for that reason, take Divine Insight rather than Power Infusion.