Time Siphon

You siphon the temporal continuity of one creature in order to empower your own essence. Choose one creature within range to make a Wisdom saving throw. On a success, the target is unaffected. On a failed save, the target 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 use reactions. On its turn, it can use either an action or a bonus action, not both. Regardless of the creature's abilities or magic items, it can't make more than one melee or ranged attack during its turn. If the creature attempts to cast a spell with a casting time of 1 action, roll a d20. On an 11 or higher, the spell doesn't take effect until the creature's next turn, and the creature must use its action on that turn to complete the spell. If it can't, the spell is wasted. A creature affected by this spell makes another Wisdom saving throw at the end of each of its turns. On a successful save, the effect ends for it.

While a target is affected by the spell, your speed is doubled, you gain a +2 bonus to AC, you have advantage on Dexterity saving throws, and you gain an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action. When the spell ends, a wave of lethargy sweeps over you. You can't move or take actions until after your next turn, and you must succeed on a Constitution saving throw against your spell save DC or suffer 1 level of exhaustion.