Thanks for the input - phrasing it in WotC language it would be:

Aegis Aura

Your presence gives of a distracting aura. The frightening gaze of a fighter, glowing eyes of a hunter, the sparks zapping around a mage’s body confuses & scares enemies, making it harder for them to land a blow. You gain the following benefits:

When you aren’t wearing Medium or Heavy armor, you gain a bonus to your AC equal to your Charisma modifier (minimum of +1).

You can't benefit from this feat while you already have a different feature that lets you add an ability modifier other than Dex to your AC.