1. Purity removes magic of light and grants immunity to it for three turns (this spell is only available to warrior mages. It is in the same category as healing).
2. Dispel removes all spells cast on a unit, both positive and negative. It can be used on both friendly and enemy units.
3. Some races have abilities to remove negative spells from their troops - Tidal Wave for Naga priestesses or Break Chains for Orc warrior heroes who are developed along the Tears path (Dispel removes spells affecting morale, initiative, movement range, and physical damage from all units).