Tactics: Curator

Strategy
The fight against the Curator is considered a gear check for new Karazhan raid groups to overcome by improving their equipment, maximizing their enchantments and showing raid discipline by bringing enough buff consumables with them, before being able to progress towards the harder bosses behind him. Like Attumen, there is little to memorize about strategy. In the end, it all comes down to a minimum level of damage output and mana endurance.

The bulk part of this fight is a repeating cycle of two phases: a Flare Phase, which lasts 100 seconds followed by an Evocation Phase, which lasts 20 seconds. Once the Curator's hit points drop below 10%, he will enter a Rage Phase which is similar to the Flare phase but where he will no longer summon Flares. If he's not killed within 10 minutes, he will go Berserk and wipe out the entire raid in a few seconds.

The fight is initiated by the main tank engaging the Curator, immediately starting the first Flare Phase. Positioning for the rest of the raid is not overly important, but noone should be standing outside of the healers' healing range.

Flare Phase
During this phase, the Curator will continously deal moderate melee damage against the main tank and summon an Astral Flare every 10 seconds for which he will spend 10% of his total mana. The Astral Flare immediately aggroes a random player and start advancing into his direction, dealing out a chain-lightning-like AoE attack on up to three players in its vicinity for about 700-800 arcane damage per second. The adds come with an initial threat threshold on their first chosen target, so it is rather difficult (but also unneccessary) to have them tanked away from the raid.

All damage dealers of your raid should concentrate entirely on destroying these Astral Flares within the 10 seconds before the next Flare spawns or else there will be multiple adds present at a time and damage output on the raid will quickly exceed your healers' capability of keeping the raid alive. Threat is not an issue, so everyone can use their highest DPS abilities.

The Curator will also cast a Hateful Bolt every 10 to 15 seconds on a semi-random player other than his current target. The chance for a player of becoming the victim of a Hateful Bolt is influenced by the players' current health level and his position on the Curator's threat table. This can be utilized by a raid that designates one player - preferably a warlock with a high health pool - as a soaker for most of the Hateful Bolts by having him constantly keep up DoT effects on the Curator in this phase. Equippig this player with arcane resistance gear negates a substential amount of the damage from the Hateful Bolts, making the fight somewhat easier and mana-preserving for the healers.

Warlocks can cast Curse of Doom somewhere between the summoning of the 4th and 6th Astral Flare which makes certain it will go off during the Curator's vulnerable Evocation Phase.

Evocation Phase
Immediately after the Curator summons the 10th Astral Flare with the last of his mana, he will enter a state of Evocation for 20 seconds in which he will refill his mana up to maximum level again. While he does so, he will go completely inactive and all damage dealt against him will be tripled.

Your raid should first concentrate on killing the 10th and last add before switching damage over to the Curator, since this add still ought to be killed before the Evocation phase ends - and killing it early means granting your healers a few seconds break for normal mana regeneration.

Cooldown and single-use abilities that temporarily increase a player's damage output should be saved up for this moment and be activated at the beginning of the phase to quickly kill the last Astral Flare and to make the most out of the Curator's temporary vulnerability.

Shadow Priests can ignore the last Astral Flare and should immediately focus their damage on the Curator, since in conjunction with Vampiric Embrace and Vampiric Touch they will be more useful to their group by refreshing a lot of their mana and health during this phase.

Once the Curator has finished refilling his mana bar, the fight will continue normally with the next Flare Phase (or the Rage Phase, if his health was brought down below 15% during Evocation).

Rage Phase
Once the Curator's hit point level drops below 15%, he will stop summoning Astral Flares but increase his melee damage output and cast Hateful Bolts more frequently instead. This simply means for the healers to give the main tank and the victims of the Hateful Bolt more attention while everyone else just nukes down the remaining hit points of the Curator.