Shadow Killer Practice
Those operatives who choose the Shadow Killer Practice are master assassins, the spiritual practitioners who combine their finely honed skills with mystical aid to vanish from sight and neutralize their targets with poison-coated weapons.
Venomous
Shadow Killer Practice: 3rd, 5th, 9th, 13th, and 17th level You gain proficiency with the poisoner's kit, and you can apply a poison as a bonus action.
Additionally, you learn to create a number of special poison vials. Over the course of a short or long rest, you can create two doses of poison. You must have a poisoner's kit in order to create these doses. Your doses can only be used by you, and they lose their potency at the end of your next short or long rest.
As an action, you can use one of your doses to coat one vibroweapon, one slug cartridge, or one wrist launcher dart. A creature hit by the coated weapon must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Intelligence modifier), taking 1d4 + your Intelligence modifier poison damage on a failed save or half as much on a successful one. Once applied, the poison retains potency for 1 minute before drying.
The quantity and damage of your doses increases at higher levels, to three and 2d4 at 5th level, four and 3d4 at 9th level, five and 4d4 at 13th level, and six and 5d4 at 17th level.
Dark Arts
Shadow Killer Practice: 3rd level You learn to combine poison and stealth to perform assassination techniques. When you deal Sneak Attack damage to a creature you may choose to forgo two of your Sneak Attack dice to make the attack a dark art.
Dark Arts save DC = 8 + your proficiency bonus + your Intelligence modifier
Envenomed Art
You attempt to poison the target. The target must make a Constitution saving throw or be poisoned until the end of your next turn.
Hallucinatory Art
You attempt to blind the target. The target must make a Wisdom saving throw or be blinded until the end of your next turn.
Vanishing Art
You feint to momentarily disappear from your target's purview. The target must make a Dexterity saving throw. On a failure, you can move up to 10 feet without provoking opportunity attacks from the target.
Poisoner
Shadow Killer Practice: 9th level You are a master of poisons. Targets of your poisons cannot have advantage on the saving throw made to resist your poison, and you have advantage on Dexterity (Sleight of Hand) checks made to conceal the application of poisons.
Additionally, when you apply poison to a weapon or its ammunition, that poison can affect an additional hit or an additional piece of ammunition, and when you deal Sneak Attack damage with an attack that would include poison damage, you can change your Sneak Attack damage to poison damage.
One With the Dark
Shadow Killer Practice: 13th level You learn to partially enter the spirit realm. As an action, you can become invisible as an enhanced effect, along with anything you are wearing or carrying, for 1 hour or until you dismiss this effect (no action required). This invisibility ends early immediately after you deal damage to a creature or you force a creature to make a saving throw.
Once you use this feature, you can't do so again until you finish a long rest. While you have no remaining uses of this feature, you can expend one of your poison doses from your Venomous feature to use this feature again. When you do so, your maximum doses decreases by 1 until the end of your next long rest.
Shades of Night
Shadow Killer Practice: 17th level Your familiarity with poisons and the spirit realm has opened up new paths of life and death for you. Your Evasion feature now applies to Constitution saving throws as well as Dexterity saving throws.
Additionally, whenever you create poison using your Venomous feature, you can change the damage type to acid, cold, fire, lightning or necrotic. When you do so, and you deal Sneak Attack damage with a weapon coated with your poison, you can also change your Sneak Attack damage to the chosen type.