Ilyykur's mantle

Ilyykur's mantle was an arcane abjuration spell that gave the caster some protection against various types of magical attacks.

Effects
This spell gave the caster a protective aura that covered the body in a soft, form-fitting glow. If the caster had a familiar that was no larger than Small and it maintained contact with the caster, then the familiar was afforded the same magical protection. Ilyykur's mantle was particularly good at protecting the caster from enchantment/charm spells, but also granted a minimal boost to protection from all other types of spells. One additional feature was that all damage from electrical attacks (lightning bolt, shocking grasp, and the like) was reduced by half. The spell's duration was one minute for every experience level of the caster.

Components
In addition to verbal and somatic components, this spell required a natural, uncut, unpolished gem of any value.

History
This spell was published in "Volo's Guide to All Things Magical" and became generally known to the magical community.