Every living thing is bound to their plane of origin by threads that tether their essence there. Through dedicated training of the body and mind, the monks of the Way of the Untethered Self learn to master those ties to travel great distances, defend against dangers, and dispatch foes. 

Untethered Grasp

Beginning at 3rd level, you can teleport allies and enemies alike. As an action, you can expend one Ki point to touch a creature and teleport with them to an unoccupied space within 30 ft that you can see. If the creature is unwilling, they can make a Charisma saving throw. On a success, they do not teleport with you.
When you use your Flurry of Blows, you can replace one of the unarmed strikes with a use of this feature without spending an additional ki point. 
When you reach 11th level in this class, the distance you can teleport increases to 60 ft.

Untethered Movement

Beginning at 6th level, your ability to teleport short distances is second to none. Whenever you spend a Ki point to use your Step of the Wind feature, you can replace any or all of your movement for that turn with teleportation. You can only use this special movement if your current speed is greater than zero. 

When you reach level 15 in this class, you can teleport in this way even when you do not take use the Step of the Wind feature. 

Tethering Presence

Your manipulation of the treads that bind creatures to this plane extends to others. When you see a creature within 30 ft of you targeted by an effect that would cause them to teleport or travel to another plane of existence (including banishment), you can use a reaction to expend 2 Ki points to cause that creature to make a Charisma saving throw (which they may choose to fail). On a failure, the effect fails and the originator of the effect takes 3d10 force damage. 
At level 17, the range for this ability increases to 100 feet. 

Untethered World

Beginning at 17th level, your mastery of the tethers spans the entire world and beyond. You can use 8 Ki points to cast Teleport or Plane Shift. Your Wisdom is the spellcasting modifier for these spells. Once you cast a spell in this way, you cannot cast either again until you finish a long rest.