Lightning Spear with Avatar of Fire will usually do only fire damage from the hit, but the exact damage depends on your gem level, supports, weapon, and whether the skill’s lightning part is fully converted or just partially converted. A key rule from the source material is that Avatar of Fire converts 50% of lightning, cold, and physical damage to fire, then prevents you from dealing non-fire damage, and it is typically used in builds that reach full fire conversion.

What that means for Lightning Spear

Lightning Spear is described as a lightning-based spear skill that throws a spear, bursts on hit, and fires secondary lightning bolt projectiles. If you add Avatar of Fire, the lightning damage that would normally remain lightning is pushed toward fire conversion, but any damage that is not converted is effectively lost because you can only deal fire damage. So the practical result is: if your Lightning Spear setup does not fully convert its damage to fire, your damage can drop a lot.

Simple rule of thumb

  • If your build has 100% total conversion to fire , then Lightning Spear can be made into a fire-scaling skill and keep most of its damage.
  • If your build has less than 100% conversion , you lose the unconverted portion and your real damage is lower than the tooltip might suggest.
  • Secondary effects that explicitly deal lightning damage are also a concern, because Avatar of Fire blocks non-fire damage.

Practical example

If a Lightning Spear hit effectively has 100 lightning damage before conversion, Avatar of Fire alone does not mean it becomes 100 fire damage. The source indicates Avatar of Fire converts 50% of lightning damage and disables the rest unless you have enough extra conversion from other sources to finish the job. That is why fire-conversion builds normally stack additional conversion, rather than using Avatar of Fire by itself.

Best takeaway

For PoE2 Lightning Spear , Avatar of Fire is only good if you are deliberately building full fire conversion and fire scaling; otherwise, it is usually a damage loss. The safest answer is: it won’t “just work” as full damage by itself.

If you want a precise number, the missing piece is your exact Lightning Spear gem level, support gems, weapon stats, and conversion sources.