Armor of Agatha

A protective frost surrounds/covers you and your gear. You gain temporary hit points of 5 for the duration. If a creature attacks you with a melee attack while you have the hit points, the creature will take 5 cold damage.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, both the temporary hit points and the cold damage increase by 5 for each slot

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