Weapon file / Cross-universe
Nuln Oil
Nuln Oil is the joke that becomes a real build engine. The cross-universe paint pot slows enemies and applies Oiled, increasing the damage they take from fire. It is a setup weapon, not a solo win condition.
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Confirmed behaviour
Nuln Oil is a cross-universe weapon usable by both 40K and Age of Sigmar champions. Auroch describes it as dousing enemies in black wash: affected enemies slow down and become vulnerable to fire damage. The status is called Oiled. It combos with weapons that inflict Burning.
The official feature also notes that status effects can affect champions, not only enemies, and that some enemies are immune. The Nuln Oil file therefore starts with a simple rule: apply the oil before the fire, and do not assume every target can be oiled.
- Universe: cross-universe.
- Confirmed effect: slowdown plus increased fire damage (Oiled).
- Confirmed synergy: Burning weapons.
- Reported evolution: Mordant Earth from Nuln Oil + Hourglass.
Hourglass and Mordant Earth
The October community table pairs Nuln Oil with Hourglass and lists Mordant Earth in both universes. It is the only recipe reported in both campaigns, so it appears twice in a raw count. The official material confirms the base weapon and Oiled status but not the evolution or the companion.
The reported trigger is the familiar maxed weapon plus boss chest. If you are testing it at launch, check both universe variants separately: a shared recipe name does not guarantee shared availability or identical behaviour.
Evidence level: Nuln Oil and Oiled are official. Hourglass → Mordant Earth is community-reported in both universes.
How to use it
Apply Nuln Oil to the front of the pack, then let a fire weapon hit the oiled group. The order matters. If the fire lands first, the oil is only a slow; if the oil lands first, the fire gets the multiplier. Build a wide overlap so both effects cover the same enemies.
Do not hold Nuln Oil as an emergency button. Its value is persistent setup, and a slow-moving pack is easier to kite through. Against fast Khorne units or a Tyranid surge, the slow can be as important as the damage bonus.
- Oil first, burn second.
- Keep the oiled zone between you and the horde.
- Pair with an actual fire source; do not expect Nuln Oil to carry damage alone.
- Respect immune enemies and test the interaction at launch.
Build and users
Auroch has not announced a dedicated wielder. Nuln Oil is a support weapon for any champion who can spare a slot and already has a fire source. The status effect guide explains the Oiled/Burning interaction in detail, and the evolution finder tracks the reported Mordant Earth line.
Pre-launch note. Values and evolution triggers can change before 10 November 2026. Community pairings are labelled and should be verified in the launch build. See the update log for newer information.
Sources and evidence
Editorial methodOfficial claims, press observations and community reports are kept separate. Where Auroch has not published a value, this guide says so instead of filling the gap.