Bone armour

You touch a willing creature who isn’t wearing armor. Bones form and wrap around your body to create a makeshift armour. You are considered to be wearing weightless light armour with proficiency, and your base AC is increased by +2. As a reaction, after you take damage to your hit points you can roll 1d6, and increase your temporary hit points by that amount. This spell has no effect if you are already wearing armour.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, increase the temporary hit points gained by 1d6 for each slot level above 2nd. Additionally when you cast the spell using a spell slot of 4th level or higher, you gain an additional +1 to your base AC for each 2nd slot level above 2nd.