Greater antidragon aura

Greater antidragon aura was a protective spell used by clerics.

Effects
When cast, this spell created a protective aura around the targets that glowed with a phosphorescent green. This spell increased the strength of any attack against dragons and related creatures, any blow was instead absorbed by the dragon. It also provided extra protection against spells cast by dragons and their ilk. Additionally, it protected against a dragon's attempt to posses or influence a creatures mind.

Components
In addition to verbal and somatic components, the spell required a focus: a container, such as a reliquary, that held a sacred relic. The relic was often a piece from the sword of a dragon slayer. The sacred relic had to have a value of at least 500 gp.