Anti-Magic Shell

You surround yourself with a field of necrotic energy that repels harmful magic. For the duration of the spell, you have advantage on saving throws against spells, and resistance to the damage from spells. Furthermore, when a spell allows you to make a saving throw to take only half damage, you instead take no damage if you succeed on the saving throw.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the shell lasts for an additional two rounds for each slot level above 2nd.