Agreth the Nether Spider — guide

In short

Agreth the Nether Spider is a Doom Tower boss and one of the nastiest floors on any difficulty. You farm her for Tower rewards — shards, books, gems and legendary set pieces on the higher floors. She is also a hard test of whether your team can keep debuffs under control: without reliable cleansing you simply fold.

Mechanics

• Venom Nails — an AoE hit on the whole team that applies Poison for several turns; it repeats once for every Spiderling currently without an active buff. More Spiderlings means far more Poison.
• Brood Feast — summons up to four Spiderlings, gives them Counterattack and hits your whole team together with them. Agreth usually opens the round with this.
• Watcher — she counterattacks whenever her Turn Meter is reduced, and that damage ignores DEF. Turn Meter reduction is also only half as effective on her (Inertia), while the retaliation hits at full strength.
• Toxic Wave — at the start of her turn she hits everyone and all Poison debuffs on your team deal their damage instantly. On top of that, hitting her with a champion that has Poison extends that champion's debuffs and applies Poison Sensitivity, while hitting her with a clean champion applies Poison to them.
• Almighty — damage dealt to her based on MAX HP is capped at roughly a tenth of her MAX HP per hit, so one huge nuke will never delete her.
• Immunity to Stun, Freeze, Sleep, Provoke, Fear, HP swap and HP equalise effects, and to cooldown increase.

What your team needs

• Constant cleansing or Block Debuffs: Poison must be gone before Agreth takes her turn, otherwise Toxic Wave erases half your health bars.
• Speed: your cleanser should be the fastest champion, ideally ahead of the boss, and it helps if they carry Protection or Stoneskin.
• Accuracy around 200–250 for mid floors, higher for the top ones — you need Decrease DEF, Weaken and HP Burn to land.
• HP and DEF on everyone, not just one tank: Poison hits the whole team, and shields or Block Damage make the fight far calmer.
• Decrease ATK on Agreth, plus damage through HP Burn or Poison, which ignores her MAX HP cap.

Teams

• Budget: Doompriest, Mausoleum Mage, Geomancer, Venomage, Kael — Doompriest passively cleanses one debuff every turn, Geomancer brings HP Burn, Kael adds damage and Poison.
• Mid-game: Underpriest Brogni, Doompriest, Geomancer, Stag Knight, Dark Kael — Brogni covers the team with shields and Block Debuffs while Stag Knight lands Decrease DEF and Decrease ATK.
• Endgame: Duchess Lilitu, Acrizia, Gnut, Marius the Gallant, Mithrala Lifebane — Lilitu keeps Block Debuffs up and revives, while Acrizia and Gnut hit off MAX HP in many small hits and stay inside the Almighty cap.

Common mistakes

• Reducing Agreth's Turn Meter — Watcher retaliates for massive DEF-ignoring damage.
• Letting the boss take her turn with four or five Poison stacks on the team and no shields.
• Bringing control champions: Stun, Freeze and Provoke do nothing here, those slots are wasted.
• Ignoring Spiderlings — every one of them without a buff adds an extra Venom Nails hit.

Tips

• Build your cleanser on Speed plus Perception or Accuracy sets; they need no damage stats at all.
• Lifesteal and Immortal sets on your damage dealers soften the Poison ticks considerably; Toxic on your own champions does nothing here since the boss supplies the Poison.
• Take survivability masteries plus Warmaster or Giant Slayer for steady boss damage.
• On auto-battle, disable control skills and Turn Meter reduction and leave only cleansing, shields and damage.
• Clear Spiderlings before Agreth's turn, but never at the cost of a cleanse — keeping the team clean always comes first.