The Spirit of Battle is an item that can be won on Treasure Hunter. When used on a Slayer mask or its helm alternative, it will reset their kill count, which will reset the benefits that the masks give. A mask which has yet to reach the kill count to convert it into a helm provides additional Slayer experience, bonus damage, and a double-drop every 10th kill, but only when on a Slayer task for that monster. A slayer mask/helm that has already reached the required kill count provides no such benefits, which is why the Spirit of Battle is a helpful item.
These monster-specific slayer masks/helms provide additional benefits not affected by the Spirit of Battle.
Although it is possible to use the Spirit of Battle on a mask that hasn't reached the required kill count, it would be wasteful to do so.
Slayer masks and helms | |
|---|---|
| Masks | |
| Helms |
 Black Demon Dagannoth Troll Dead Hand Keening Petrification Little Kings Jellyhead Blood Foulness Devilry Automatons Kuraski Grotesquery Verdant Wyrm Parched Wyrm Aquanites Mutation Warping Darkness Airut Frozen Wyrm Ganodermic |
| Related |
 Spirit of Battle |
