Remove Insulation 2014

You target a creature within range, and that creature must succeed on a Fortitude saving throw or become less resistant to lightning damage. A creature with immunity to lightning damage has advantage on this saving throw. On a failure, a creature with immunity to lightning damage instead has resistance to lightning damage for the spell's duration, and a creature with resistance to lightning damage loses its resistance for the duration. A creature without resistance to lightning damage that fails its saving throw takes double damage from lightning for the spell's duration. Remove curse or similar magic ends this spell.

If you cast this spell using a spell slot of 6th level or higher, the duration is 24 hours. If you use a spell slot of 8th level or higher, a creature with immunity to lightning damage no longer has advantage on its saving throw. If you use a spell slot of 9th level or higher, the spell lasts until it is dispelled.