A Soulknife possesses powerful psionic potential. They channel this reservoir of inner magic into tangible blades of psychic energy, striking at their victims' minds. They find easy employment as members of thieves' guilds, being particularly sought after as assassins, since their signature psychic blades leave behind no visible wounds.
As a Soulknife, your psionic abilities might have haunted you since you were a child, only revealing their potential when your psychic knives first appears. Or you might have sought out a reclusive order of psionic assassins and spent years learning how to manifest your deadly blades.
Source: Unearthed Arcana 66 - Fighter, Rogue, Wizard
Starting at 3rd level, as a bonus action, you can create a magical blade of shimmering psychic power from one or both of your hands. While one of your hands is manifesting a blade, you can't hold anything in that hand. You can dismiss one or both blades at any time (no action required), and they disappear if you're incapacitated.
The blade is a simple melee weapon with the finesse, light, and thrown properties. It has a normal range of 30 feet and a long range of 60 feet, and it deals 1d6 psychic damage on a hit. If you throw the blade as part of an attack, it vanishes immediately after it hits or misses its target. The blade otherwise disappears the instant it leaves your hand.
Starting at 3rd level, you can focus your psionic power to give yourself an extraordinary ability. When you finish a long rest, you gain one of the following benefits of your choice, which lasts until you finish a long rest:
Starting at 9th level, your Psychic Blades can now stoke terror within a target: When you damage a creature with your Psychic Blade, you can force the target to make a Wisdom saving throw (DC equal to 8 + your proficiency bonus + your Intelligence modifier). On a failed save, the creature is frightened of you until the start of your next turn. On a successful save, the creature isn't frightened and is immune to your Terrifying Blade for 24 hours.
Starting at 13th level, you can weave a veil of psionic static to mask your physical presence. As an action, you can magically become invisible, along with anything you are wearing or carrying, for 10 minutes. This invisibility ends if you make an attack or if you force a creature to make a saving throw.
You can use this feature a number of times equal to your Intelligence modifier (minimum of once), and you regain all expended uses when you finish a long rest.
Starting at 17th level, you can sweep your Psychic Blade directly through a creature's mind. As an action while you have at least one Psychic Blade manifested, you can force a creature you can see within 30 feet of you to make an Intelligence saving throw (DC equal to 10 + your proficiency bonus + your Intelligence modifier). If you are hidden from the target, it has disadvantage on the save. On a failed save, the target takes 12d6 psychic damage, and it is stunned until the start of your next turn. On a successful save, the target takes half as much damage and isn't stunned. One of your Psychic Blades vanishes after using this feature.
You can use this feature a number of times equal to your Intelligence modifier (minimum of once), and you regain all expended uses when you finish a long rest.