Allatos' Shield of the Lightbringer

The caster calls upon the power of the Allatos, the god of the sun, and summons a radiant barrier of divine energy to protect an ally. Until the start of your next turn,  the ally has a bonus to AC of 2 + the caster's Charisma Bonus, including against the triggering attack

If cast with a spell slot at least 2 levels higher, the target is shrouded in the light of Allatos and engulfed in an aura of energy that deals 2d6 damage (Constitution save for 1/2) to any enemy in contact with the targeted ally when the spell is cast. The Caster may choose if this aura deals Radiant or Fire damage. Any enemy who enters the aura for the first time on their turn or who starts their turn in the aura suffers the damage (Con Save for 1/2)

The damage increase by 1d6 for each spell level above 4th