Bloodstalker Assassin

Whether through twisting of blades or use of serrated weapons, the Bloodstalker Assassin ensures their victim always bleeds. A master of anatomy, applying precise strikes meant to open up and exsanguinate their target, the Bloodstalker is an adept at causing lasting injuries. 

Hemorrhage

3rd-level Bloodstalker Assassin feature

Beginning at 3rd level, you are well versed in the art of causing injuries. Whether twisting your blades or using serrated arrows, you always ensure your victims bleed. You gain the following:

• When you deal Sneak Attack damage to or critically strike a target, you can force it to make a Consitution saving throw (DC = 8 + your proficiency bonus + DEX). If the target fails, they begin bleeding, taking 1d6 damage at the start of their turn. On a success, the creature does not begin bleeding. That creature or another creature may use an action to make a medicine check against your Hemorrhage save DC to stop the bleeding. The bleeding also stops if the target gets magically healed. This feature has no effect against undead or constructs.
• At higher levels, this damage increases. At 11th level, it becomes 2d6, and at 17th level, it becomes 3d6.

Opportunistic Strikes

3rd-level Bloodstalker Assassin feature

Beginning at 3rd level, you know how to use an opponents injury to create openings for yourself. You gain the following:

• When you make an attack against an enemy affected by your Hemorrhage feature, you may strike with your offhand weapon as part of the same action or reaction. This extra attack does not stack with the Extra Attack feature granted by some classes. You must follow the normal rules for dual wielding in order to attack with an offhand weapon. 
• You gain the Two-Weapon Fighting style.

Improved Hemorrhage

9th-level Bloodstalker Assassin feature 

Beginning at 9th level, your knowledge of bodily anatomy allows your to make incisions that are nearly impossible to close properly. You gain the following:

• Your Hemorrhage save DC increases by 1(9 + your proficiency bonus + DEX)
• You gain proficiency in medicine. If you already have proficiency in medicine, you gain expertise instead.

Vein Ripper

13th-level Bloodstalker Assassin feature

Beginning at 13th level, your strikes aim precisely at veins and arteries, giving you the following:

• You critically strike on a roll of a 19 or 20.
• Your hemorrhage save DC increases by 1(DC = 10 + your proficiency bonus + DEX).

Finishing Blow

17th-level Bloodstalker Assassin feature

Beginning at 17th level, you've mastered the art of the killing blow. Every strike of yours is without mercy, leaving your enemies battered and exsanguinated at your feet. You gain the following:

• You can now use your Sneak Attack feature twice, rather than once, per turn. The second time you apply Sneak Attack damage, you roll half the number of dice, rounded down.
• Your Hemorrhage save DC increases by 2(DC = 12 + your proficiency bonus + DEX).