To know oneself,  is to know the universe. Through study and thought those that follow the Way of the Mystic have come to master the flow of their own ki, using it to manifest spells and manipulate the planes of existence themselves.

Mystic Arts

Starting when you choose this tradition at 3rd level, you can use your ki to duplicate the effects of certain spells. You learn the Minor Illusion cantrip if you don't already know it. Additionally, as an action, you can spend 2 ki points to cast Detect Magic, Mirror Image, Phantasmal Force, or Vortex Warp, without providing material components. These spells all use your ki save DC.

Ethereal Master

Starting at 6th level, your meditations have unlocked the Ethereal Plane. Once per turn when you hit a creature with an unarmed strike you can spend 1 ki point, forcing your target to make a Charisma saving throw. On a failed save you and your target are shunted into the Ethereal Plane for a number of rounds equal to your Wisdom modifier.

While on the Ethereal Plane, you can see and hear the plane you originated from, which is cast in shades of gray, and you can't see anything there more than 120 feet away. You can only affect and be affected by other creatures on the Ethereal Plane. Creatures that aren't there can't perceive you or interact with you, unless they have the ability to do so.

You can end this effect free of action during your turn. When you do, both you and your target return to unoccupied spaces that you can see within 10 feet of the spaces you vanished from. If no unoccupied space is available within that range, you and your target appear in the nearest unoccupied space. This effect ends if you die or are incapacitated.

If you reduce your target to 0 hit points and they die in the Ethereal Plane, their body is left behind and you regain 2 ki points.

Arcane Body

Starting at 11th level, you learn to channel your inner magic into devastating blows and hone your ethereal mastery. As an action you can spend 4 ki points to grant yourself truesight for 1 minute.

In addition, when you spend 1 ki point or more on your turn, your unarmed strikes and monk weapon attacks deal force damage until the start of your next turn. During this time while in the Ethereal Plane your attacks deal an additional martial arts dice of damage.

Planar Palm

Also at 11th level you gain the ability to sever a creature's anchor to this plane. Once per turn when you make an unarmed strike you can spend 6 ki points and cast Banishment on your target without providing material components. This uses your ki save DC.

Open the Mind

Starting at 17th level, you have learned to weaponize your knowledge of existence. You can spend 1 or more ki points and force a creature you can see within 5 feet of you to make a Wisdom saving throw. On a failed save their conscience is hurled through the multiverse, they take 1d10 psychic damage for every ki point spent and are incapacitated until the end of your next turn. On a successful save they take half as much damage and are not incapacitated.