Circle of Risk Taking

You point your finger, which must be wearing the ring, at a point in space that you can see and is no more than 20 feet way from you. A 30 feet bubble of magic springs from that point, all creatures inside must make a Charisma saving throw or have their AC reduced to 0 for the duration. A creature that enters the area afterwards does not experience this effect only those that were inside it when it appeared. Creatures that exit the bubble still suffer the effects. Optionally, you may sacrifice your own AC to force a number of creatures equal to your AC - 10 ÷ 2 to automatically fail their saving throw.