Angelic Flame Shield

A green shield of magical fire protects a creature you can see within 30 feet of you. Until the start of your next turn, they have a 1d4 + your spell casting modifier bonus to their AC, including against the triggering attack, and they take no damage from Magic Missile. Any attacks that miss in that time the attacker takes 2d6 fire damage.

For each Level above second you cast this spell at adds 30 feet of range and an extra d6 of fire damage.

If you don't want to expend the spell slot you can force out more angelic power to get the same effect by taking 2d4 force damage.