Banish the Air

The caster cause all the air in an 50ft radius and up to 40ft high of the target to disappear. Any living creature within the area has the air taken out of their lungs. The victims must make a Constitution save every round; DC starts at 10 and increases by 1 each round. When the victim fails they begin to suffocate and fall unconscious at 0 hit points. The next round they drop to -1 hit point and are dying. The following round they die.