To beat all six Extremis bosses in Warhammer Survivors, complete the specific weapon evolution that counters your target before its 25-minute encounter.
Ordinary bosses reward damage and survival with upgrade chests. Extremis bosses add an equipment requirement: a powerful loadout can still leave you unable to hurt them. Your preparation starts with rescuing the right champion and revealing hidden passives, often across separate runs. The checklist below covers all six Extremis encounters, followed by the Mortarion and Nagash special stages.
Six Extremis bosses and where they appear
Warhammer 40,000 and Age of Sigmar each have three Extremis bosses. Choose your target before starting, because its stage determines which counter you need to prepare.
| Cleared | Boss | Setting | Stages |
|---|---|---|---|
| [ ] | Norn Emissary | Warhammer 40,000 | Imperial Bastion, Desert Wasteland, Death World Invasion |
| [ ] | Ghazghkull Thraka | Warhammer 40,000 | Ork Stronghold |
| [ ] | Great Unclean One | Warhammer 40,000 | Gallowdark, Imperial Shipyard |
| [ ] | Vizzik Skour | Age of Sigmar | The Great Parch, Under-Empire, The Twin-Tailed City (Aqshan realm) |
| [ ] | Skarbrand | Age of Sigmar | Bloodwind Spoil, The Twin-Tailed City (Ghyran realm) |
| [ ] | Trugg the Troggoth King | Age of Sigmar | Skrappa Spill, Gnarlwood |
How to prepare before a boss fight
Rescue the champion tied to your target’s base weapon before committing to a clear. The Warhammer Survivors character unlock guide covers those stage rescues, while the boss sections below identify the champion you need.
Collect Auspex on Desert Wasteland for Warhammer 40,000 or Arcanoscope on Gnarlwood for Age of Sigmar. Each detector reveals hidden items throughout its own setting, including the passives used in the boss-counter recipes.
Green-outlined enemies drop chests. A weapon must be maxed, and you must hold its matching passive, before a chest can evolve it. Some recipes also require the passive to reach its maximum level. Without the required preparation, the chest provides an ordinary upgrade instead.
Boss chest reward screen
A higher Chance stat improves chest reward rolls, but no boss guarantees an evolution. Prioritize the required weapon and passive early enough to leave time for chest drops before the final encounter. Every recipe below still needs an evolution chest after its listed levels are ready.
Boss counters, attacks, and safe movement
Norn Emissary
Recipe: Power Fist level 8 + Codex Astartes level 6 → Gauntlets of Ultramar.
Rescue Marneus Calgar on Death World Invasion to get a champion who starts with Power Fist. Once Auspex is unlocked, return to Death World Invasion to find Codex Astartes on the map.
Norn Emissary is immune to stun, Vulnerable, and Instant Kill. It also resists burning, poison, and slow. Build direct damage around the required evolution instead of spending support slots on effects that depend on disabling or weakening it.
Ghazghkull Thraka
Recipe: Power Klaw level 8 + Da Lucky Stikk level 9 → Bale Eye.
Rescue Yarrick on Ork Stronghold to start with Power Klaw. Surviving 15 minutes as him unlocks the weapon for other champions. With Auspex unlocked, search Ork Stronghold for Makari to obtain Da Lucky Stikk.
Da Lucky Stikk adds enemy spawns as it levels. Its required upgrades therefore increase the pressure before you reach Ghazghkull. Keep another weapon focused on the surrounding horde while you finish the passive.
Bale Eye is a short-range eye laser that inflicts Battle-Shock on Orks. Its evolution retains both Power Klaw and Da Lucky Stikk. Leave yourself an exit before moving into its range: Ghazghkull resists knockback and is immune to stun and curses.
Great Unclean One
Recipe: Ardent Blade level 8 + Tactical Rock level 9 → Weapon of the Matriarch.
Rescue Saint Celestine on Imperial Shipyard to start with Ardent Blade. Killing 1,000 Vulnerable enemies as her unlocks it for other champions. Auspex reveals Tactical Rock on Imperial Shipyard.
Tactical Rock adds 25% Corruption at level 5 and another 25% at level 9, making enemies tougher while you prepare. Avoid spreading upgrades so thinly that your damage falls behind those increases.
Weapon of the Matriarch replaces Ardent Blade with a horizontal fire strike, while Tactical Rock remains. The Great Unclean One resists poison and burning, so neither should carry your damage plan.
Vizzik Skour
Recipe: Flintlock Pistols level 8 + Ardcoat at any level → Aqshian Firestakes.
Rescue Hanniver Toll on The Great Parch to start with Flintlock Pistols. Survive 10 minutes as him to unlock them for other champions. After obtaining Arcanoscope, look for Ardcoat on The Great Parch.
Ardcoat’s unlock objective asks you to encounter three Extremis bosses. You do not need to defeat them for that objective. Its recipe also avoids the heavy passive-level investment required by several other counters.
Aqshian Firestakes replaces the pistols with ricocheting shots that deal extra damage to magic users, including Vizzik. Ardcoat stays in your loadout. Vizzik is immune to stun and Instant Kill, so keep moving instead of expecting either effect to create a safe opening.
Skarbrand
Recipe: Stormcharged Warhammer level 8 + Tactical Rock level 9 → Uskavar the Sunderer.
Rescue Rostus Oxenhammer on Bloodwind Spoil to start with Stormcharged Warhammer. Survive 10 minutes as him to unlock the weapon for other champions. Arcanoscope reveals this setting’s Tactical Rock on Bloodwind Spoil.
Uskavar the Sunderer adds a slam that reacts to nearby enemies. The evolution retains the hammer and Tactical Rock. For support damage, Skarbrand is weak to Frost, Null, and Holy, but immune to burning, poison, and stun.
Target Uskavar for your first clear. The further evolution, Ghal Maraz, needs Null Pendant, which only unlocks after defeating Nagash. Do not make that later unlock a prerequisite for this attempt.
Trugg the Troggoth King
Recipe: Fyrestorm Greataxe level 8 + Kragg Blackhammer’s Master Rune at any level → Zangrom-Thaz.
Rescue Gotrek on Skrappa Spill to start with Fyrestorm Greataxe. Survive 10 minutes as him to unlock it for other champions. Arcanoscope reveals the Master Rune on Skrappa Spill, and its unlock objective also requires reaching level 20 on The Great Parch. The rune has only one level.
Zangrom-Thaz replaces the axe with a fast triple-axe attack and retains the rune. Trugg is immune to most status effects, so concentrate on weapon damage and movement.
Trugg’s Ironshell Club covers wide, telegraphed areas and knocks you back. Move out of the marked swipe area before returning to weapon range. His back-mounted crystal fires random fire, poison, or bleed shots, so watch for projectiles while avoiding the club.
Weapon and upgrade priorities
Compare the bosses’ health scaling
Extremis health scales with your champion’s level. Each boss has a minimum of 10,000 health, so the multiplier below only takes over once it produces a larger value.
| Boss | Health calculation before other modifiers |
|---|---|
| Great Unclean One | Your level × 700, minimum 10,000 |
| Vizzik Skour | Your level × 650, minimum 10,000 |
| Norn Emissary | Your level × 500, minimum 10,000 |
| Ghazghkull Thraka | Your level × 500, minimum 10,000 |
| Skarbrand | Your level × 300, minimum 10,000 |
| Trugg the Troggoth King | Your level × 230, minimum 10,000 |
The Great Unclean One has the highest health multiplier, while Trugg has the lowest. Neither comparison removes the equipment gate. Secure the counter first, then strengthen damage that the target does not resist.
Choose support evolutions around the passives already in your loadout, and check the Warhammer Survivors weapon evolution recipes before spending levels on another pairing.
Manage surrounding enemies
Keep enough space around the boss to change direction when an attack warning appears. Chasing the large target through a packed horde can close your escape route before its own attack reaches you.
Watch for enemies that strengthen the crowd or make movement unsafe:
- Tyranid Synapse sources: These empower nearby lesser creatures. Destroying the source briefly stuns nearby lesser bioforms.
- Skaven Bell of Doom: Its support can make surrounding rats more resilient. Remove that advantage when it blocks your approach.
- Globadiers and Death Guard hazards: Reposition outside poisonous clouds instead of concentrating on the boss while standing in them.
For Malum Caedo, the best Warhammer Survivors crowd-clearing build uses Chainsword sweeps, ranged fire, and artillery to keep routes open. Use that crowd-control role to support your required boss counter, not replace it.
Mortarion and Nagash special stages
Defeat all three Extremis bosses in a setting to unlock its special stage. Mortarion and Nagash occupy fixed map locations instead of arriving at the Extremis spawn time.
| Boss | Stage | Stage time limit | Base health before Corruption and mode multipliers |
|---|---|---|---|
| Mortarion | Perils of the Warp | 30 minutes | 7,500 |
| Nagash | Necropolis | 25 minutes | 2,000 |
Both bosses are immune to stun and Instant Kill. Treat their table values as base health, not a promise that every run presents the same effective health pool.
Mortarion’s unlock
Mortarion flies and carries the scythe Silence. Locate him on Perils of the Warp while managing the stage timer. Defeating him unlocks Purity Mode for Warhammer 40,000.
Nagash’s unlocks
Defeating Nagash unlocks Null Pendant. Completing Necropolis unlocks Purity Mode for Age of Sigmar. The pendant also opens the later Ghal Maraz evolution mentioned in Skarbrand’s preparation.
Common reasons boss attempts fail
Some failed attempts come from mode rules or misunderstood status effects, not an unfinished damage build.
| Problem | Cause | What to change |
|---|---|---|
| The final boss never appears | Endless War removes the final boss | Leave Endless War off when attempting an Extremis clear. |
| The encounter arrives sooner than expected | Fast Attack doubles the mission clock | Plan against the displayed mission timer, or leave Fast Attack off while learning the route. |
| A stunned enemy still attacks | Stunned stops movement, not attacks | Continue avoiding attack warnings even when an enemy stops moving. |
