The Way of the Empty teaches the learner to part their Soul from their body, to achieve true peace of mind and body.

Departed Soul

Starting from 3rd level, you can once per long rest you can split your soul from your body, sending it to the ethereal plane. This effect will last for 30 seconds (or 5 turns) and while it is active you can move your body and soul separately, are immune to all psychic damage and the charmed and frightened condition and you can expend 1 Ki point as a bonus action to deal 1d10 psychic damage to creatures in touch range of your soul. However, if something like a phase spider currently resides in the spot you travel to it can attack you.

As a bonus action, you can choose to end this effect early and when doing so your soul will teleport back into its body.

Soul Seperation

At 6th level, you can send a creature's Soul to the Ethereal plane, violently ripping it from its body. You can do this once per rest when an attack hits.

This effect lasts for 2 turns and while it is active the body doesn't move or use its actions, however, if the creature is attacked its soul returns. The Body is True Neutral while the effect lasts and is willing to communicate and socialize as it does not remember the combat.

Ethereal Armour

Beginning at 11th level, you can as an action spend any amount of ki points to grant any creature within 10 ft. 1d8 temporary hit points per point expended.

Etherealness

At 17th level, you gain resistance to bludgeoning, slashing and piercing damage coming from a non-magical source. Your Soul can now stay in the Ethereal plane for twice as long. Monsters on the ethereal plane will actively avoid you and only attack if you provoke them.