Conduit

You form a temporary tether between yourself and a creature or object within range. While tethered, you can use a bonus action on subsequent turns to alter the gravitational pull:

• Lightened Step: The target's weight is reduced, granting an advantage on Dexterity (Acrobatics) checks and increasing its jump distance by half.
• Heavy Burden: The target's weight increases, reducing its movement speed by 10 feet.

You can end the tether as a free action. A hostile creature can attempt a Strength saving throw at the end of each of its turns to break free. 

3rd-level or higher: You can tether up to two creatures or objects at once. 

5th-level or higher: The effects of Lightened Step (jump distance increase) and Heavy Burden (speed reduction) are doubled.