The way of the Searching soul focus on meditating and allowing the soul to escape from the body into the world, these monks spend days straight meditating letting their souls become free, and their discipline is unmatched even among other monks. The way of the Searching Soul was founded by an old man who's body had failed him, He learnt to separate the soul from the body so he could once again interact whith the world. Some say the Old man still roams the world as a spirit guiding those who need his help.

Separate

At 3rd level, you can meditate for 6 seconds, when you do this spend 1 Ki point, you then roll charisma whith a DC= to 20- your level (at level 20 even critical fails are a success). if you succeed, your soul will separate, and appear in the same place you are no sitting prone. your spirit has all the same mental stats, but all physical stats are identical to your Charisma + your modifier for said stat. All your moves are the same, except all damage dealt as a spirit is Physic. Your spirit's flying speed is your Charisma modifier x 20, and you can move through all none magic material. Your are semi-transparant, and all attack rolls against you have disadvantage, as well as having advangtage on steal checks (you make no sound or smell). you are immune to 

Invisible Spirit

At 6th level, you can spend a bonus action and 1 Ki point to make your spirit invisible for as long as you want. You can revert back to being visible as a bonus action any time.

Unwilling Servitude

At 11th level, when you enter the same space as another creature you can try to posses them by using 2 Ki point for evry 3 challenge rating (or level) of the creature (minimum of 1). Both creatures make a charisma saving through, whith the target having disadvantage, and the highest one wins. On a successful possession the creature is now under the control of the monk, the monk then must make a wisdom saving throw whith a DC = to the creatures challenge rating (or level), on a failed save the monk still possesses the creature but falls prone for 1 round. Evry turn after the possession the target can make a charisma check to throw out the monk.

Split soul

When you reach 17th level, when you separate your soul from your body, you can make part of it stays behind, and controls your body. Both the spirit and the body now have disadvantage on all mental saving throws, and checks (Charisma, Intelligence, Wisdom), until they either reunite or the split soul uses a bonus action to remove itself from the monks body.