Vella's Viscous Vacuum

For the duration of the spell, the air is removed from a 20ft cube on a point you choose. Neither sound nor fire can exist within this spells area of effect. Creatures within this spells area of effect are under the same conditions as the SILENCE spell as well as being unable to breathe. 

Casting: On the initial casting of this spell, any creature caught with this area must make a constitution saving throw, on a failed save take 6d10 bludgeoning damage as the air is ripped from their lungs, and are pulled to the center of the cube, on a successful save take half damage but are still pulled. Creatures that don't need to breathe automatically succeed.

Suffocation: After the initial casting of this spell a creature that needs to breathe that starts its turn within the spell's area or enters it, starts suffocating and must make a DC 15 Constitution saving throw. On a failed save, the creature falls unconscious. At the start of its next turn, it drops to 0 hit points and is dying, and it can't regain hit points or be stabilized until it can breath again. On a success, the creature isn't affected this round. For each consecutive round after the initial saving throw that the creature stays within the vacuum or moves through it, the DC for that creature is increased by 5. A creature can't hold its breath to prevent being affected by the spell. Death saving throws made within the spell's area by creatures that require breathing automatically fail. Creatures that don't need to breathe are immune to this effect.

Death: A creature that dies while under this spells effects can't be brought back to life by a spell or effect that can't replace the body or affected organs.