Psiknife
Rare amongst those who practice the roguish arts is one who has true psionic potential. When trained to unlock the psionic power within themselves, these Rogues can learn to become Psiknives. Focusing their wondrous minds they can manifest blades of pure mental power, communicate telepathically, and augment their considerable skills with psionic enhancement.
Psionic Awakening
3rd-level Psiknife Archetype feature
You have unlocked the dormant potential of your mind. This mental power is represented by a pool of Psi Points equal to your Rogue level. You regain a number of Psi Points equal to your Intelligence modifier (minimum of 1) when you finish a short rest, and all of your Psi Points when you finish a long rest. Your Psi Points also fuel the following abilities:
Mystical Skill. Whenever you fail an ability check, you can expend 1 Psi Point to gain a bonus to that roll equal to your Exploit Die, possibly turning a failure into a success. Should this change the outcome, it is a visibly psionic effect.
Telekinetic Leap. As a bonus action, you can expend 1 Psi Point and 10 feet of movement to jump up to 30 feet in a line, even if this distance would exceed your remaining speed.
Telepathic Link. As an action, you can expend any number of Psi Points, choosing one creature that you can see per Psi Point spent. You and all of those creatures become part of a telepathic network for a total number of hours equal to your Intelligence modifier (minimum of 1 hour). So long as you all remain on the same plane of existence you can communicate telepathically with each other.
Psi Blade
3rd-level Psiknife Archetype feature
You can conjure a blade of pure mental power. As part of an attack, or as a bonus action, you can conjure one Psi Blade in an empty hand and make one attack with it. Your Psi Blades use the statistics of a dagger, but it deals psychic damage on hit, you can use Intelligence for its attack and damage rolls, and its thrown range is doubled.
The Psi Blade emits bright light in a 5-foot radius, its attacks leave no visible marks on your target, and you can dispel it at-will.
The damage die of your Psi Blade grows to match the size of your Exploit Die.
Empowered Blades
7th-level Psiknife Archetype feature
Your Psi Blades are infused with a portion of your willpower. You can expend Psi Points to use the following features:
Mind Rend. When you hit with a Psi Blade and add your Sneak Attack damage bonus, you can use Cunning Strike to reduce the damage by 2d6 and force the target to make an Intelligence saving throw against your Exploit save DC. On a failure, it can’t take reactions until the beginning of your next turn, and on its next turn it can only do one of the following: move, use one action, or use one bonus action.
Sentient Strike. When you miss with a Psi Blade attack, you can expend 1 Psi Point to gain a bonus to the attack roll equal to your Exploit Die, possibly turning a miss into a hit.
Metaphysical Shift
7th-level Psiknife Archetype feature
You can shift your place in reality with the wondrous powers of your mind. You can use your Cunning Action to expend Psi Points (up to your Intelligence modifier) and teleport up to 20 feet per Psi Point spent, appearing in an unoccupied space of your choice that you can see within that range.
Shimmer
13th-level Psiknife Archetype feature
You can erase your presence from the minds of others. As an action, you can spend 1 Psi Point to veil yourself with psionic energy as if you had cast the invisibility spell on yourself.
This effect does not require concentration, but it instantly ends if you make an attack, cast a spell, or touch a creature.
Mental Scourge
17th-level Psiknife Archetype feature
You can focus the power of your Psi Blade to strike directly at your foe’s mind. When you use Mind Rend to force a creature to make an Intelligence saving throw, you can reduce your Sneak Attack bonus by an additional 2d6 (for a total of 4d6) to empower the strike further. On a failure, the creature is Stunned until the start of your next turn.
You also regain one expended Psi Point at the start of each of your turns in combat.