Thundering Armor

You infuse a creature's armor with pulsing energy, increasing its protection and knocking a single foe away with an intense reverberation. Choose a friendly creature within range that is wearing armor. The subject gains a +2 bonus to AC until the end of its next turn. You can also choose a hostile creature within 5 feet of the ally. That hostile creature must make a Strength saving throw. On a failed save, it takes 2d8 thunder damage and is pushed 10 feet away from your ally. On a successful save, the target takes half damage and is not pushed. You cannot cast this spell on yourself. The sound of this spell can be heard up to 100 feet away.