Hydra Guide
Feathersnare Swamp · ATK 280 · Power 330 000
Agony Blast scales with your Poison stacks, so every stone, crevice and dispel is really a decision about that one number.
Before you pull
Plaguebearer: enrage at 8 minutes
8m after entering battle, Hydra becomes Enraged, unleashing Agony Blast with much greater frequency.
Hydra is immune to every debuff and impairment except Taunt.
Control heroes do nothing here.
Bring
Stats
Health300 000
Defense2 250
MovementVery Fast
Battle duration300s
Rewards
Gems600
Speedups25h
Gold1M
Wood1M
Ore750K
What you must not do
- Watch the raid's stack count, not just your own. Agony Blast hits everyone every 20 seconds and scales with it
- Never let a stone explode. One Legion poisoned beats forty
- One Legion per crevice, not two
- Do not dispel a Legion that is carrying Mana Infusion. You would be deleting your own damage
The mechanics
2Unstable ManastoneStones appear around the Lair on a timer.
3Poisonous CrevicesCrevices open across the ground.
4Dispelling Manastone, and its hidden costEach time Hydra casts Poison Barbs, 2 Dispelling Manastones appear.
5Ongoing damage
The fight, phase by phase
5 phasesAgony Blast: the reason Poison matters
Every 20 seconds, Hydra damages every Legion in the Lair. Base damage is 1% of maximum Unit Count, and it rises with every stack of Poison that Legion is carrying.
This is what wipes raids. At one stack it is a rounding error. At six or seven stacks, every 20 seconds takes a large bite out of every Legion at once, and there is nothing to dodge. A raid does not die to Hydra's attacks. It dies to its own stack count.
So read every mechanic below as: does this add a stack, and is that worth it?
Agony Blast
Every 20s, Hydra deals Magic Skill damage to all Legions within its Lair (1% of the Legion's maximum Unit Count). Legions take increased damage for each stack of Poison.
Unstable Manastone
Stones appear around the Lair on a timer.
| What you do | What happens |
|---|---|
| Nobody gathers it | It explodes: Damage Factor 1,200 to every Legion in the Lair, plus 1 Poison stack each |
| A Legion gathers it | Only that Legion takes 1 Poison stack, and gains 1 stack of Mana Infusion: +25% damage dealt |
The maths is not close. An ungathered stone poisons forty Legions; a gathered one poisons one and pays it back with a quarter more damage.
Send your biggest damage dealers. Mana Infusion stacks, so a strong Legion collecting repeatedly becomes the reason the boss dies before the timer.
Unstable Manastone
In the first phase, multiple pieces of Unstable Manastone periodically appear within Hydra's Lair. Shortly after appearing, ungathered Unstable Manastone will explode, dealing Magic Skill damage to all Legions within the Lair (Damage Factor 1,200) and inflicting one stack of Poison on all Legions who take damage. If Unstable Manastone is gathered, the Legion that gathered it will take one stack of Poison and one stack of Mana Infusion. Each stack of Mana Infusion increases' Legion's damage dealt by 25%.
Poisonous Crevices
Crevices open across the ground.
- A crevice with nobody standing on it explodes: Damage Factor 1,200 lair-wide, 1 Poison stack for everyone
- A crevice with a Legion standing on it does not explode. That Legion absorbs the poison instead: 1 stack, for them alone
You need at least one Legion per crevice. More than one is wasted, and it is a wasted Poison stack too, so assign them and keep everyone else on the boss.
Poisonous Crevices
In the second phase, Hydra opens up multiple poisonous crevices in the ground. Shortly after opening up, crevices where no Legions are standing will explode, dealing Magic Skill damage to all Legions within the Lair (Damage Factor 1,200), and inflicting one stack of Poison. If Legions are standing on a crevice, this will prevent it from exploding; the Legion will absorb the poison from the crevice, inflicting one stack of Poison.
Dispelling Manastone, and its hidden cost
Each time Hydra casts Poison Barbs, 2 Dispelling Manastones appear.
Gathering one heals your lightly wounded units and clears all Toxicity.
It also clears all Mana Infusion. The +25% per stack you built up in phase one is gone with the poison.
So this is a real decision, not a free pickup. A stacked-up damage Legion should stay poisoned and keep hitting. The Legion sitting on eight stacks with nothing to show for it should take the stone.
Dispelling Manastone
Each time Hydra casts Poisonous Barbs, two pieces of Dispelling Manastone will appear in its Lair. Once gathered they can heal a Legion's lightly wounded units and clear all Toxicity and Mana Infusion effects.
Poison Barbs
Hydra unleashes a series of poisonous barbs, dealing Magic Skill damage to all Legions hit by them (Damage Factor 800), and inflicting one stack of Poison.
Ongoing damage
- Miasma: forward arc, 20% of maximum Unit Count, plus a Poison stack. Never stand in front
- Poisonous Pulse: a globule at a random Legion, Damage Factor 800 to everyone nearby, plus a stack. Spread out
- Poison Barbs: Damage Factor 800 and a stack, and it is what spawns the Dispelling Manastones
- Rancorous Strike: a charge that knocks its path Airborne, Damage Factor 500
- Foul Ambush: knocks every Legion out to the edge of the Lair. Expect to have to walk back
- Fang Strike is a forward arc; Tail Sweep hits everything around it
Miasma
Hydra's three heads unleash a cloud of poisonous vapor, dealing Magic Skill damage to all Legions in a forward arc (20% of the Legion's maximum Unit Count), and inflicting one stack of Poison on all Legions who take damage.
Poisonous Pulse
Hydra launches a poisonous globule at a random Legion's location, dealing Magic Skill damage to all nearby Legions (Damage Factor 800), and inflicting one stack of Poison on all Legions who take damage.
Rancorous Strike
After a short charge-up, Hydra rushes forward, knocking all Legions in its path Airborne and dealing Magic Skill damage (Damage Factor 500).
Foul Ambush
After a short charge-up, Hydra knocks all Legions Airborne, sending them flying to the edge of its Lair and dealing Magic Skill damage.
Fang Strike
Hydra tears at enemies with its deadly fangs, dealing Magic Skill damage to all enemy Legions in a forward arc (Damage Factor 300).
Tail Sweep
Hydra sweeps its powerful tail, dealing Magic Skill damage to surrounding Legions (Damage Factor 500).
Reference
All 16 skills, lair and alliance, with the full game text