Awake to the psionic power within, a Psi Knight is a fighter who augments their physical might with psi-infused weapon strikes, telekinetic lashes, and barriers of mental force. Many githyanki train to become such knights, as do some of the most disciplined high elves. In the world of Athas, renowned gladiators in the arenas of the Sorcerer-Kings are often Psi Knights, and in Eberron, the psionic kalashtar view membership in this knighthood as a special honor.
As a Psi Knight, you might have honed your psionic abilities through solo discipline, unlocked it under the tutelage of a master, or refined it at an academy dedicated to wielding the mind’s power as both weapon and shield.
Source: Unearthed Arcana 71 - Psionic Options Revisited
At 3rd level, you harbor a wellspring of psionic power within yourself, an energy that ebbs and flows as you channel it in various ways. This power is represented by your Psionic Talent die, the starting size of which is a d6.
Changing the Die’s Size. If you roll the highest number on your Psionic Talent die, it decreases by one die size after the roll. This represents you burning through your psionic energy. For example, if the die is a d6 and you roll a 6, it becomes a d4. If it’s a d4 and you roll a 4, it becomes unusable until you finish a long rest.
Conversely, if you roll a 1 on your Psionic Talent die, it increases by one die size after the roll, up to its starting size. This represents you conserving psionic energy for later use. For example, if you roll a 1 on a d4, the die then becomes a d6.
Whenever you finish a long rest, your Psionic Talent die resets to its starting size. When you reach certain levels in this class, the starting size of your Psionic Talent die increases: at 5th level (d8), 11th level (d10), and 17th level (d12).
You can use your Psionic Talent die in the following ways:
Protective Field. When you or another creature you can see within 30 feet of you takes damage, you can use your reaction to roll your Psionic Talent die and reduce the damage taken by the number rolled plus your Intelligence modifier (minimum reduction of 1), as you create a momentary shield of telekinetic force.
Psi-Powered Leap. When you make a high or long jump, you can roll your Psionic Talent die and extend the distance of the jump, up to a number of feet equal to twice the number rolled plus twice your Intelligence modifier (minimum of 1 extra foot). This extra distance costs you only 1 foot of movement.
Telekinetic Strike. You can propel your attacks with telekinetic force. Once on each of your turns, immediately after you deal damage to a target within 30 feet of you with a weapon attack, you can roll your Psionic Talent die and also deal force damage to the target equal to the number rolled.
Starting at 3rd level, as a bonus action, you can calm your mind for a moment and restore your Psionic Talent die to its starting size. You then can’t use Psi Replenishment again until you finish a long rest.
By the 7th level, you have mastered new ways to use your telekinesis:
Psionic Thrust. When you deal damage to a target with the Telekinetic Strike of your Psionic Talent, you can force the target to make a Strength saving throw against a DC equal to 8 + your proficiency bonus + your Intelligence modifier. Unless the save succeeds, you can knock the target prone or move it up to 10 feet in any direction horizontally.
Telekinetic Movement. If your Psionic Talent die is available, you can move an object or a creature with your mind. As an action, you target one loose object that is Large or smaller or one willing creature, other than yourself. If you can see the target and it is within 30 feet of you, you can move it up to 30 feet to an unoccupied space you can see. Alternatively, if it is a Tiny object, you can move it to or from your hand. Either way, you can move the target horizontally, vertically, or both. When you take this action, your Psionic Talent die decreases by one die size.
Starting at 10th level, the psionic energy flowing through you has bolstered your mind and body. You have resistance to poison and psychic damage, and you are immune to the poisoned condition.
Bulwark of Force
At 15th level, you can shield yourself and others with telekinetic force. As a bonus action, you can choose creatures, which can include you, that you can see within 30 feet of you, up to a number of creatures equal to your Intelligence modifier (minimum of one creature). Each of the chosen creatures is protected by half cover for 1 minute or until you’re incapacitated.
Once you use this feature, you can’t do so again until you finish a long rest, unless you decrease your Psionic Talent die by one die size to use this feature again.
When you reach 18th level, your ability to move creatures and objects with your mind is matched by few. If your Psionic Talent die is available, you can cast the telekinesis spell, requiring no components. Your spellcasting ability for the spell is Intelligence. When you cast this spell, your Psionic Talent die decreases by one die size.