Armorbrand

You brand a rune of protection onto a creature of your choice. The rune can absorb up to 5 hit points of damage, but is applied in an inactive state. A creature with an Armorbrand on it can activate the rune as a reaction to taking damage. The rune absorbs as much of the damage as possible before dispersing. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the hit point value of the rune increases by 5 for each slot level above 1st.