|Release||4 April 2014 (Update)|
|Destroy||Are you sure you wish to destroy your Treasure Hunter prize? You cannot reclaim it.|
|On death||Always kept|
|Examine||Use this on a completed slayer mask/helm to allow you to complete it again!|
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.