Energy Necklace

You create 8 balls of pure energy, from your hands. They will follow you, wherever you go. You can throw one or two balls at the enemy as an attack. When you do so, it's considered as an action. Attack bonus of this action is always +4 and it always deals 2d6+2 lightning damage. Attack will be with disadvantage, when your target has a shield. If your target's armor class is higher than 18, attack deals additional 1d4 thunder damage. When you're about to lose concentration, you can use one of the balls, to get advantage on your saving throw to maintain concentration. After you lost concentration, every ball you still have vanishes.