Time Slippage

8th-level enchantment (temporal) (clockwork)

Casting Time: 1 action
Range: 60 feet
Components: V, S, M (the heart of a chaotic creature of challenge rating 5 or higher, worth 500 gp)
Duration: Concentration, up to 1 minute

You ensnare a creature within range in an insidious trap, causing different parts of its body to function at different speeds. The creature must make an Intelligence saving throw. On a failed save, it is stunned until the end of its next turn. On a success, the creature’s speed is halved and it has disadvantage on attack rolls and saving throws until the end of its next turn. The creature repeats the saving throw at the end of each of its turns, with the same effects for success and failure. In addition, the creature has disadvantage on Strength or Dexterity saving throws but advantage on Constitution or Charisma saving throws for the spell’s duration (a side effect of the chronal anomaly suffusing its body). The spell ends if the creature makes three successful saves in a row.