Slow

You alter time around up to six creatures of your choice in a 40-foot Cube [Area of Effect] within range. Each target must succeed on a Wisdom saving throw or be affected by this spell for the duration.

An affected target's Speed is halved, it takes a -2 penalty to AC and Dexterity saving throws, and it can't take Reactions. On its turns, it can take either an action or a Bonus Action, not both, and it can make only one attack if it takes the Attack action. If it casts a spell with a Somatic component, there is a 25% chance the spell fails as a result of the target making the spell's gestures too slowly.

An affected target repeats the save at the end of each of its turns, ending the spell on itself on a success.