Ignitable Spirit (3.5e Invocation)

For the next 24 hours you gain fire resistance equal to 5 times your charisma bonus with a maximum of 5 times your level. For example, a 2nd level warlock with 18 in charisma would have a fire resistance of 10. A 4th level warlock with 18 in charisma would have fire resistance of 20. A 6th level warlock with 18 in charisma would have fire resistance 20.

Variants: Change fire to some other type of energy (other than sonic or force). For example, cold resistance would be called Icy Spirit. You may also make it so that you choose the energy resistance whenever you cast the invocation. In this case, the resistance changes to 4 times your charisma bonus with a maximum of 2 times your level. In this case it is called Dark One's Own Resistance.