Time Bubble

You unleash a Huge bubble of time energy. Each creature in a 20-foot Emanation originating from you makes a DC 15 Constitution saving throw. On a failed save, a creature is frozen in time and loses it's ability to make a turn for 1 round. The creature is also paralyzed until the end of the next round. This results in you taking a second full turn immediately after the turns of the creatures with successful saves. On a successful save, a creature moves through time slower than normal, halving their movement speed for one round.

Using a Higher-Level Spell Slot. The DC increases by 1 for each spell slot level above 7.