Create Atmosphere

Choose a point within range. From that point, a shimmering silvery sphere of atmosphere of 20ft radius appears, containing clean, breathable atmosphere. This sphere spreads around corners. You can designate any amount of creatures you can see to pass into and out of the sphere freely. Other creatures must make a Strength saving throw to cross the boundary.

Undesignated creatures that are in the area when you cast the spell make this save with advantage, but if they fail they are pushed out of the area to a free space within 5ft of the sphere