Death-Mark Assassin

A nobleman looks out of his upstairs window onto the discontented masses, when out of the shadows a cloaked figure jabs a knife between his ribs, freeing the people from his tyranny.

A group of cultists can be found trying to raise the body of a local hero as an undead, then a blade from the shadows takes out the cultists and sends the champion's soul back to the afterlife.

When a soul needs to be sent (or sent back) to the afterlife, these assassins get called to guarantee that the soul of that being gets disconnected from that body. These assassins can see the mark of death on all targets who cross their path, and by striking that mark, they have an easier time dispatching foes, living and dead alike.

Marked for Death

Focusing on a target (action) causes you to see a spot on the target glow a wispy white. Roll with emphasis (roll two dice and take the result furthest from 10) to attack this spot and gain bonus damage (necrotic) on your attack roll against this creature. Being hit requires you to make a saving throw of 14, a failed roll causes you to lose focus on the target, you must wait a turn to refocus on the target.

At 3rd level, attack bonus is a d4.

At 9th level, attack bonus is a d6.

At 13th level, attack bonus is a d8.

At 17th level attack bonus is a d12.

 

 

Assistance to the Grave

At 3rd level, you gain the ability to partially ignore the resistances of your living enemies, and to completely ignore the resistances of undead targets. Partial resistance now only removes 1/4th of the damage. 

You gain advantage on attack rolls against undead enemies.

At 5th level, sneak attack ignores resistances from enemies.

At 10th level, necrotic damage becomes extra effective on undead enemies.

 

Shadowstalker

Starting at 9th level, you gain the ability to see through dark spaces and can use 1/3 your rogue level to lower the requirement for your attack to be a critical attack, three times per long rest and resets one charge per short rest.

60 ft. of Darkvision, if race already has darkvision you gain the ability to see as you would during daytime.

Impostor

At 13th level, you gain the ability to unerringly mimic another person’s speech, writing, and behavior. You must spend at least three hours studying these three components of the person’s behavior, listening to speech, examining handwriting, and observing mannerisms.

Your ruse is indiscernible to the casual observer. If a wary creature suspects something is amiss, you have advantage on any Charisma (Deception) check you make to avoid detection.

Death Strike

Starting at 17th level, you become a master of instant death. When you attack and hit a creature that is surprised, it must make a Constitution saving throw (DC 8 + your Dexterity modifier + your proficiency bonus). On a failed save, double the damage of your attack against the creature.