Arcane Armor (Asteria)

You have learned to wrap yourself in a defensive shell of arcane force.

While you are unarmored or wearing light armor, your Armor Class equals 13 + your spellcasting ability modifier. If you have more than one spellcasting ability, choose Intelligence, Wisdom, or Charisma when you take this feat.

When you cast a spell of 1st level or higher, you gain a +1 bonus to AC until the start of your next turn.

When you are hit by a weapon attack, you can use your reaction to reduce the damage by an amount equal to your proficiency bonus.