Holy Shield

4th-level Abjuration
Casting Time: 1 action
Range: Self
Components: VSM (a shield)
Duration: 10 minutes

A shield you are wielding becomes light as a feather while expanding with radiant protection, shedding bright light in a 10-foot radius and dim light for an additional 10 feet. You can end the spell early by using an action to dismiss it, and it also ends early if you drop your shield.
While holding this blessed shield, it provides you with a +2 bonus to your armor class. This bonus stacks with existing magical bonuses on the shield, to a maximum of +3. If a creature misses you with an attack, and the creature is within 5 feet of you, the shield flashes with holy fire. The attacker takes 2d8 holy damage. After you are missed by 8 attacks while affected by this spell, the spell ends.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the shield may block an additional 2 attacks for each spell level above 4th.

Source: Homebrew