Telepath

This subclass is based off the Keeper of the Lost Cities book series. With it, you can locate someone by tracking their thoughts, shield your own, and even break someone's mind, rendering them useless and immobile. Note: at level 2, you get Telepathy automatically, but must choose between Detect Mind and Print Thoughts. At level 10, you must choose between Erase Memory and Mental Shield.

Telepathy

Starting at level 2, the subclass gains telepathy to speak to any creatures (regardless of language) within a 100 ft. radius. Any creature that speaks a different language than you will hear your words in their own language. They cannot respond if they do not have telepathy of their own, but if they do, you will hear their words in your own language as well.

Memory Print

Starting at level 2, you can transfer one still image of your choice from your mind to a piece of paper once per short rest.

Locate Mind

Starting at level 2, you can pinpoint another creature's location by tracking their mind as long as they are within 150 ft. radius of you.

Shield Thoughts

Starting at level 6, you can shield your thoughts from unwanted intruders. Can use at will to shield your mind for anywhere from 1-6 hours. For each additional hour past the first you will suffer one level of exhaustion. When your mind is shielded, any creature looking to use telepathy to enter your mind will have to make an Intelligence check with a DC equal to 1d20 + your Wisdom modifier. On a success, your shielding fails. On a fail, your shielding holds and the creature is unable to enter your mind.

Erase Memories

Starting at level 10, you can reach into the mind of any creature in your line of sight. Unless they allow you to enter, you must make an Intelligence check against their Intelligence. If they succeed, you enter their mind, and can erase one major memory that occurred no more than 30 days ago. They can make a Wisdom saving throw if they wish to try and resist the effects. If it succeeds, you are thrown from their mind and suffer one level of exhaustion. If it fails, you succeed in erasing the memory and exit their mind.

Mental Nook

Starting at level 10, you can hide your consciousness inside a mental nook within your head. Any attempts at entering your mind will succeed, but they will not find anything but emptiness. Your speed becomes 0, and you can take no actions. You are immune to psychic damage while your conscious is hidden. You also have a +5 to any saving throw made to resist having your mind broken (see class feature), or remove fix the breakage of your mind if it had already been broken. At will, you can un-hide your consciousness, removing all the previously listed effects. 

Mind Break

At level 14, you can touch a creature and enter their mind. You must make a single Intelligence check contrasted by a Wisdom/Constitution (roll 1d20, add both your Wisdom modifier and your Constitution modifier) check from the person you are attempting to break. If your check fails, you are ejected from their mind and fail to do anything. If your check succeeds, you must then make another Intelligence check. On a success, you break your opponent's mind, rendering them incapacitated, dealing 1d10 psychic damage every day from when the spell was cast, and setting all their stats to 1. Every day, the broken creature can make a DC15 Wisdom saving throw. On a success, they will break free from the mind break, resetting their stats and removing their incapacitation. On a fail, they remain broken.