Heroic: Hagara the Stormbinder

Short guide for 10 mans (how our raid did the 1st kill):

Setup
- 1 Tank (druid)
- 3 Healers (druid, priest, shaman)
- 6 DDs (hunter, mage, rogue, warlock, priest, death knight)

Normal phase
The boss was tanked to the edge of the platform, to the south near the portal. Two healers stood in front of her at a little more than 5y distance, to soak the shattering ice cast (only people in front of her are targetted by it if there are any).
Three DDs were assigned to stand 3y apart behind her in melee range (even ranged), and another three stood a little further away behind them. They would soak the ice lances, and because no one is hit by shattering ice, it didn't matter if some stack got higher than 3. A healer did backup, helping out wherever the stacks would get too high otherwise.
Ice tomb targets moved next to her, but mind that it can break LoS between a healer and a tank. Set the position carefully.
If you look closely at her weapon enchants, you can already tell which special phase will come first.

Ice phase
The fastest way to kill the binding crystal is to stay near them until they are (nearly) destroyed. For the first one, gather close to a previousely marked position (better be always the same) and kill it fast. The ice wave should not reach you before it is gone. The next ones can't be burned this quickly. When the wave is close, avoid it through the bubble in the center (jumping in awards a small speed advantage). You shouldn't skip more than one wave per crystal or the damage might be too low.
Targets of frostflake should also run into the bubble to be dispelled, to avoid ice patches.
We used aspect of the cheetah which made this phase much easier. But don't get hit by the ice blocks that fall from the skies, they're instant death because of the daze.

Storm phase
The most important thing here is speed. Followed by pet management. A misplaced imp can cause high lighning damage to the group, leading to a wipe. Always keep your pets in the center! Tank the melee add where it spawned, kill it fast. The healers and anyone without a conductor task should stand right in the center, do not spread. Now here's probably the most complex moment of the fight, where everyone needs to know exactly when they have to stand where.

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• Assign two people per set of two conductors (one small and one big one)
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• They already stand in position to connect the add's conductor to the south with the next one, to the south east of the platform, when the add dies
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• Don't wait, both players now run to the next one (east), activating it asap, then they go back to the center or they take too much damage
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• The next set of players are already in position to activate the one to the north east of the platform, and proceed the same way as the previous group: they instantly move to the one to the north
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• The exact same thing is being done to the opposite (west) side of the room.

The east part was done by druid/hunter and WL/mage, the west part by DK/rogue and rogue(clos)/spriest.
Healers need to find out when it's best to use raid cooldowns (you will need them). Additionally, the hunter was in aspect of the wild during the complete phase. Basically, this is all about activating the conductors as fast as possible while not taking as little damage as possible.

Enjoy! :)

For Druids on the Ice Phase, you can shift forms to drop Frostflake, though make sure to dip into the bubble to do so as it still drops the ice patch on the ground.

If you are having trouble with the achievement Holding Hands I put together a simple guide to doing it solo with a pet or with a friend.

Simple WoW Guide - Holding Hands Solo lvl 100
https://www.youtube.com/watch?v=gt-kyR7gxrY