Hydross the Unstable Strategy Guide (part 1)

Pre-Game
Despite Hydross being slightly reduced in difficulty in the 21 March 07 patch (crushing blows removed), he is still much more difficult than Gruul,and slightly harder than Magtheridon. Please recognize that even with this strategy and all the requirements fullfilled, you will probably need hours of well executed attempts before you can down him. Execution must be perfect.

Required Attunement
Serpentshrine Lair

Hydross in water form
Ideal Class Balance

DPS: 12
Tank: 4
Heal: 9

A typical breakdown would be:
Rogue: 3
DPS Warrior: 1
Hunter: 1
Mage: 4
Warlock: 3

Shaman: 2
Priest: 4
Paladin: 2
Resto Druid: 1

Tank Druid: 2
Tank Warrior: 2

Specific groupings are not listed because what is best for one guild may not be best for all. It depends on the cumulative skill, gear and layout of the classes within the raid. The two things needed are: resistances for all 4 tanks and DPS-centric groups.

Note that you could technically use 2 warriors to tank the adds, rather than 2 druids. However, warrior aggro generation (especially on multiple targets; 2 each in this case) is significantly less than that of a druid. Druids also deal more damage in their tanking form, which aids greatly in downing this boss.

Gear Minimum
Gear must be extremely high quality. Every member should be able to look through their equipment and be able to say to themselves "I only need a few more upgrades from Karazhan or Gruul's lair."

Melee DPS: Karazhan quality weapons, lvl70 blue armor or better
Healers: Mix of Karazhan quality blue/purple armor or better

Tank Druid: Frost/nature resistance gear mix, hitpoint gear.
Tank Warrior: One tank with a set of nature resistance gear, One tank with a set of frost resistance gear. Block rating is irrelevant. You will need the epic lvl70 resistance gear (your stats, such as defense, will decrease when you wear this. These mobs can critical strike, but the resist gear is far more important than the defense you're giving up).

Although druids only tank during add transitions, a recap of the fight will show that druids take more damage than the warrior tanks. This means that you must fullfill the resistance gear requirements for all 4 tanks and have resistance auras and/or totems at all times.

Below are benchmarks to gauge your resistance gear and ability to tank. If your incomming hits are more than this, you need more resistance gear to beat the encounter.

Frost tank's average hit taken should be around: 3,100. An unresisted hit with 100% mark will typically hit for nearly 11,000.
Nature tank's average hit taken should be around: 2,900. An unresisted hit with 100% mark will typically hit for nearly 10,000.
Druid's average incomming hit (single add) should be around: 3,100 with an unresisted max hit of around 6,000.

Minimum Consumables Requirements
Every major consumable possible for your class. This includes full raid flasks.

Melee DPS use a Flask of Relentless Assault, Fel Strength Elixir, Elixir of Major Agility, Winterfall Firewater, DPS food, and any other damage increasing consumable. Poisons do not work on this fight: bring Adamantite Sharpening Stones.

Ranged DPS use Flask of Firepower, Adept's Elixir, Elixir of Major Fire/Frost/Shadow Power, and any other damage increasing consumable.

Tanks use Flask of Fortification, Defense Potion, Elixir of Mastery, stamina increasing food; anything that will increase HP or mitigation. Note: Stoneshield-type potions are useless because all "melee" damage is elemental (resistance gear check, not armor).

Healers use Flask of Mighty Restoration, Mana Regeneration Potion, Elixir of Healing Power; anything that will increase your healing efficiency or the amount of mana you have.

Frost Protection Potions are a major advantage during frost stages. Although not completely necessary, they are definitely nice to have. Neither Nature or Frost Protection Potions are totally necessary. However, Hydross' Water Tomb ability has a high chance of hitting you since it can chain off other people; making it handy to use Frost Protection Potions before the encounter begins. Vile Sludge is rather insignificant in damage, and has a much lower chance of applying on you during the fight, making Nature Protection Potions a relatively excessive use.

Miscellaneous Requirements
Talent Specs: All specs must be pure PvE. Your team needs every boost they can get. This goes double for DPS.

UI Modifications: Main Tanks need a timer and must give vocal warning of impending vulnerability stacks.

Third Party Programs: Ventrilo or similar voice communication program. The raid must be vocal about needing heals, upcoming tank swap warnings, mana, add aggro status, and so on.

Wipe Recovery


Hydross the Unstable wipe recovery positions

The best way to wipe is to make a habbit of always dying to the right-hand side of the red line and inside the blue highlight. The Boglord must be killed every hour that it respawns. Assembly line adds may be killed to increase resurrection range by a small amount, but it is ill advised to risk Hydross agro.


Boss Abilities

Bad Luck Probability
Low. With proper strategy execution, luck is only a factor with Water Tomb. This can be minimized by staying away from the tanks and general spreading out.

Hydross the Unstable has about 4 million HP.

Mark of Hydross
Stacks either nature (poison phase) or frost (water/frost phase) vulnerability every 15 seconds: 10%, 25%, 50%, 100%, 250% extra damage. This applies to everyone in the raid. You cannot out-range or avoid it by standing behind a wall (line of sight). There is no way to remove this buff other than waiting the 30 second duration for it to wear off. The mark will only effect abilities/melee damage in the phase they were recieved in, because only that type of affliction is being recieved by your raid.

Water Tomb
Stuns the targets for 4 seconds and deals massive damage. Anything inside 8 yards of the target will also be affected and the Tomb will jump from person to person as many times as it can, given that the targets are less than 8 yards from each other. It will stuns your DPS (the one thing you cannot afford to lose is DPS), and if the tomb chains to too many people, it will result in a death. Losing a person will result in losing the encounter.You must spread out. He will cast this about every 7 seconds during his frost phase only. This is affected by Mark of Hydross: full tick marks at 100% vulnerability will kill someone if unhealed. This spell will target any random non-MT.

Rogues may avoid this by vanishing the same moment he targets you to cast the ability. There is a slight lag time in the time Hydross turns and the time he casts, which allows you to avoid the spell. You must have the "target's target" user-interface option enabled and be ready to Vanish the instant he turns to you. This is very valuable to the raid because it will save 2-4 melee much needed DPS time in avoiding the stun and it will also save healer mana.

Vile Sludge
Reduces damage delt and healing done by 50%. Deals 500 dmg per second when unmodified by Mark of Hydross, with a duration of 24 seconds. This spell is cast about every 15 seconds during his poison phase only. The damage is affected by Mark of Hydross. This will randomly cast on anyone in the raid. Dealing with this minor inconvenience is mentioned periodically below. Note however, that a raid could (in most cases) ignore the effects of this spell and results would be the same. This is removable with magic immunities such as Divine Shield or Cloak of Shadows.

Summon Water Elemental
Spawns 4 adds of one type in 4 corners around Hydross (imagine the corners of an imaginary box, with him being in the center) after each cleansing/poisoning. These are triggered by stepping over invisible boundaries in the immediate area. The locations of the two triggers and the relative position of the adds are shown in the positioning diagrams. In frost phase, Hydross summons 4 Pure Spawns of Hydross (water elementals), in poison phase he summons 4 Tainted Spawn of Hydross (poison elementals).

Pure Spawns of Hydross has around 55,000 HP

Tainted Spawn of Hydross has around 62,500 HP

Enrage
Explaination: Occurs 10 minutes after engaging Hydross. The damage of his outgoing melee hits and his abilities is multiplied to an amount impossible to deal with. For example, 1 tick of Water Tomb will kill a raid member on full health. He will have completely killed your raid within 15 to 30 seconds of enraging.


Strategy

Fight Overview
Hydros the Unstable is sitting in two beams of light, which purifies his body. This also gives him the ability to purify the adds coming down the "assembly line." When you move him out of his beams, he becomes poisoned (he emotes "Aaghh, the poison..."), and uses poison abilities only. When you move him back between the beams, he's repurified (emotes "Better, much better.") and only uses frost abilities.

Hydross begins in his frost/water state. He switches whenever he crosses the trigger lines (shown on diagrams below). Whenever he switches, he spawns 4 adds. Switching does not cleanse the mark but he will cease using abilities/damage types of that resistance, rendering the mark inert. The mark increases damage by more and more over time, thus forcing a switch after a certain time (15 seconds per mark stack; 5 seconds before 250% being the absolute maximum as 250% will 1 shot the tank; thus about 1 minute 10 seconds is the most time you can stay in one phase). At 10 minutes he enrages. He is tanked by two warrior tanks; one for each phase, equipped with frost and nature resistance gear accordingly. There are also druid tanks in mixed resist gear, who are used in both phases to collect the adds towards the middle.

Estimated Fight Length: 10 minutes.
Maximum Fight Length: 10 minutes, 30 seconds. There are roughly 30 seconds after his 10 minute enrage where you can attempt to kill him as he kills your remaining raid.

Phase 1 Overview
This phase is from the pull to first swich. You finish off the assembly line adds, but Hydross doesn't spawn his own adds till phase 2. Details below.

Phase 2


Hydross the Unstable poison/nature phase positions

This diagram is a snapshot of where people should be standing when poison phase (phase 2) begins. When the boss's phase changes and adds spawn, the tank moves from 1 to 2. When adds are down, 3 and 5 move to 4. About 5 seconds before the switch to water phase, the boss will be brought east to a point on the threashold of the trigger shown on the water diagram (this is so the tank only needs to take a few steps backwards to change the phase). 5-10 seconds from transitioning to the poison phase, druid tanks must move to their spots in the phase 3 diagram and aggro-insensitive ranged need to spread out.

This phase's positioning is flexible.

Phase 3


Hydross the Unstable water/frost phase positions

This diagram is a snapshot of where people should be standing when the water phase (phase 3) begins. When the boss's phase changes and the 4 adds spawn, the tank moves from 1 to 2. When adds are down, 3 and 5 move to position 4. About 5 seconds before the switch to poison phase (phase 2), the boss will be brought west to a point on the threashold of the trigger shown on the poison diagram (this is so the tank only needs to take a few steps backwards to change the phase). When 5-10 seconds from transitioning to the poison phase, 6's need to move to 7's to ensure the tanks don't get hit by Water Tomb. They must stay in spread out positions until the phase is near the end or they will spread Water Tomb to each other.

Aggro sensitive ranged must be on the east side of the poison phase trigger in case they pull temporary agro. This includes ranged DPS and main tank healers.

This phase's positioning must be perfect.