Armor of Stone

For the duration, arcane force surrounds you, appearing as jagged plates of stone. You gain 40 temporary hit points for the duration. While these temporary hit points exist, you have resistance to bludgeoning, piercing, and slashing damage, vulnerability to thunder damage, and your speed is reduced by 5 feet.

When the last temporary hit point is expended, each creature within 10 feet must succeed on a dexterity saving throw or take 3d10 bludgeoning damage.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher , the temporary hit points increase by 10 for each slot level above 5th.