Elemental Purity

The spell was created by Stanslo Brighsky, a Giant of Entaña, during his descent into madness, as he sought to become pure energy.

The spellcaster must focus on a gem worth no less than 10,000 GP (it is NOT consumed by the casting of the spell) and choose one of the following damage types: acid, cold, fire, lightning, or thunder. The gem will immediately change color to match the energy type chosen and it maintains that color until the spell is cast again. 

Any creature damaged by the spellcaster does not benefit from any resistance to the damage type chosen until the spell ends. Moreover, the intensity of power produced by this spell even overcomes immunity to that damage type. Any creature damaged by the spellcaster, using the chosen energy type, is treated as having resistance to that damage type instead of immunity. 

Finally, until the spell ends, the spellcaster gains resistance to the energy type chosen (if the spellcaster has resistance, from any source other than a spell or magical item, they gain immunity).