Mist Stalker

 As you grew up, you always felt something was off. Something was different. Why could you see phantasmal images?  Are they even shapes? No. Those are creatures. Were those creatures even there?  Those creatures are safe, aren't they?  Yes. They are friends.

One day your curiosity got the best of you one day as you approached one. For but a moment, those shapes became tangible. They became real! You watch them give a brief knowing smirk, then they become corporeal again. Just as quickly as the moment came, it ended. Now, something doesn't feel off, something new feels right.

Level 3: From Nowhere

Starting at 3rd level, you gain the ability to Misty Step as a bonus action and ignore the spell's components (V, S, M). On a successful Misty Step, your next melee attack gains advantage on the turn you Misty Stepped. Doing this does not trigger attacks of opportunity and can be used to successful escape being grappled and restrained.

This ability can be used equal to your proficiency bonus for every long rest. Half as much reacquired on a short rest (once per day).

Level 9: Soul Cleave

At 9th level, on the start of your first turn, if you perform sneak attack after Misty Stepping, you attack the connection between body and soul, dealing additional damage equal to your dexterity + proficiency modifier. In addition, the first attack will crit on 1 less than normal (ie. natural 20 becomes 19 or 20) and disables the creature's ability to use reactions until the start of their turn if they fail a constitution saving roll (DC:8 + Dexterity Modifier + Proficiency Bonus).

Level 13: The 6th Sense

You gain 1d4 uses of Misty Step.

At 13th level, your instincts give you the ability to sense the specific location of those around you within 60 ft. This ability is not inhibited by light, lack of light, or opaque objects (ie. walls, water, rock, etc.). Because of this unnatural sense, you gain the ability to Misty Step through solid objects, but only in the direction of the entity you sense. Once you the Misty Step is complete, your presence is masked for 1 turn or 6 seconds. Those in the room must succeed on a perception check vs. advantaged stealth check in order to detect you.

Level 17: Ethereal Return

Upon reaching the 17th level, up to 3 times per day, you can use your reaction to gain resistance to all damage from one attack (both physical and magical). The full damage rolled against you is stored within the essence of your veins. When you Misty Step, you can choose to let your reappearance explode, dealing all stored damage force damage to everything within a 15 ft radius. Weapon and sneak attack damage happen normally in tandem with the force damage. In addition, everything within the radius rolls a strength saving throw (DC:8 + Dexterity Modifier + Proficiency Bonus). On a fail, it is forcefully pushed 30 ft from your location. On a success, it is forcefully pushed 15 ft. 

This effect hits automatically.  The stored damage can exceed your maximum hit points and dissipates on a long rest.

This ability can be used 3 times per long rest.