Commedore's Ravishing Pressure Field

A sphere of heavy energy distorts out in a 20-foot-radius sphere within range. Each creature in that area must make a Strength saving throw or be stunned until their next turn. 

A creature starting their turn in the radius of the sphere must make a Strength saving throw or be stunned until their next turn. After a creature has failed three of these saving throws inside the radius of the sphere, the effects last for the duration and the creature is knocked prone, the creature stops making these saves.

 When cast at higher levels, increase the radius of the spell by 10 feet .