The Harbinger of Death is a rogue who has made a pact with the inevitability of mortality. Cloaked in shadows, they bring an aura of impending doom, mastering the art of death-dealing with every strike.

Mark of the Doomed

At 3rd level, you can mark your target for death. As a bonus action, you can choose one creature you can see within 60 feet of you. Until the end of your next turn, your attacks against the marked creature deal an additional 1d6 necrotic damage, and the creature has disadvantage on saving throws to resist being frightened. If the marked creature is reduced to 0 hit points while under this effect, you gain temporary hit points equal to your rogue level.

Additionally, when a marked creature is reduced to 0 hit points, you can use your bonus action to immediately mark another creature within 60 feet of you. You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses after a long rest.

Death's Whisper

At 3rd level, you gain proficiency in the Intimidation skill. If you already have proficiency, you gain expertise. You can activate this feature when you make a Sneak Attack. The target must make a Wisdom saving throw (DC = 8 + your proficiency bonus + your Dexterity modifier) or be frightened until the end of your next turn, feeling the icy touch of mortality. Additionally, when you activate this feature, the attack deals an extra 1d6 necrotic damage. You can use this feature a number of times equal to your proficiency bonus, and you regain expended uses after finishing a long rest.

Grim Harvest

Starting at 9th level, you learn to harvest the essence of death. When you successfully use your Cunning Action to Dash, Disengage, or Hide immediately after reducing a creature to 0 hit points, you regain hit points equal to your rogue level plus your Wisdom modifier.

Shadow of the Reaper

At 13th level, you become a true Shadow of the Reaper. You can move through other creatures and objects as if they were difficult terrain. When passing through a creature, you can deal 1d10 necrotic damage to it, but you cannot harm the same creature more than once in the same round. If you use this feature while hidden and pass through an enemy, that enemy is vulnerable to attacks until the end of your next turn, granting you advantage on your next attack against it. You can use this feature a number of times equal to your proficiency bonus, and you regain expended uses after finishing a long rest.

Soul Reaver

Upon reaching 17th level, you become a harbinger of souls. Once per turn, when you reduce a creature to 0 hit points, you can use a bonus action to transfer its soul into your blade. Your next successful melee attack within 1 minute deals additional necrotic damage equal to your rogue level plus your proficiency bonus, and you gain temporary hit points equal to the damage dealt.