Countblood

Hurried footfalls of leather boots on cold stone echoed from the underground chambers, accompanied by panicked and labored breathing. His half-plate was torn asunder, bloody gashes on his shoulder from the ripped metal. He stumbled, gurgling and coughing, his white-knuckle grip staunching the bloody wound on his neck, as his mace dragged on the stone behind him, loosely held by his left hand. His eyes darted frantically behind his shoulder. Veiled by darkness, he saw two bloody irises quickly dart from the darkness to the stonework above him. Cursing under his breath, he turned around and pushed himself against the wall, mace held limply ahead of him. As the painfully silent seconds passed, he felt his heart beating faster and faster in his chest. He felt like his mouth was dry and sticky, and that the walls were closing in. His breath was anxious and panicked, and as he saw the glint of red eyes to his left he swung wildly, slamming the mace into the stone. But in the instant he swung his mace, succumbing to his panic, he could only watch in horror as a set of red eyes, sharpened fangs and grinning lips plunged into him at an unnatural speed, a set of claws puncturing his chest and setting his heart to rest.

This was the prey of a Countblood. A rogue blessed or cursed by an ancient vampiric entity to hunt, Countbloods capitalize on their prey's panic, blood, and their mistakes to make deadly melee strikes and to continue hunting their prey until they are nothing but a meal. Sometimes they are chosen by high Counts, like Strahd or Dracula as unholy assassins, or other times they are the forgotten cattle of high vampires, with cursed blood flowing through their veins that grans them unnatural powers.

Hunt

At 3rd level, whenever you deal sneak attack damage to a creature with a melee weapon attack, you can choose to imbibe their essence, marking them as your prey where you gain a number of benefits against that creature. You can add your sneak attack if you hit your prey with a weapon attack, even if there is not an ally within 5ft of the creature, or you do not have advantage on the attack roll, provided you don't have disadvantage on the attack roll and you've hit your prey with an attack since your last turn, which includes any attacks you've made against them as a reaction.

If your prey misses an attack roll and they are within your reach, you can use your reaction to make a melee weapon attack against them. This attack cannot benefit from sneak attack.

You can only have one marked prey at a time and you can choose to end a Hunt, requiring no action.

Creature of the Night

Beginning at 3rd level, because of the altered blood that flows in your veins, you gain a climbing speed equal to your walking speed and you do not need to sleep, instead gaining the benefits of a long rest after 6 hours of light activity (such as reading a book.). At 6th level, you can move up, down, and across vertical surfaces, and upside down across ceilings while leaving your hands free.

Unnatural Speed

Beginning at 9th level, the speed at which you strike your prey has increased dramatically. If your prey hits you with an attack and you use your Uncanny Dodge feature, you can also make a melee attack against them if they are within reach. This attack cannot benefit from sneak attack.

Furthermore, whenever you use your Cunning Action to dash, you can also make a melee weapon attack in addition to this, provided you moved at least 10 feet and the target is marked as your prey. If you hit with this attack, your prey cannot target you with an attack of opportunity during this movement.

You can use this feature an amount of times equal to your proficiency bonus, and regain all expended uses at the end of a long rest.

Drain

Beginning at 13th level, whenever you roll a 20 on an attack roll with a melee weapon against your prey you can drain them of their essence, where you gain temporary hit points equal to half of the total damage dealt, and your prey suffers the following effects until the start of their next turn:
- Their speed is halved.
- They have disadvantage on Strength and Constitution saving throws.
- They have disadvantage on all ability checks and attack rolls.

Furthermore, while you have these temporary hit points, your speed is doubled and you have advantage on all melee weapon attack rolls made against your prey. However, you lose all these benefits, including those stated above, once your prey either reaches zero hp, you switch to a new prey, or your temporary hit points reach zero.

This requires no action to use, and you can use this feature an amount of times equal to your proficiency bonus, and gain all expended uses back at the end of a long rest.

Death Incarnate

Beginning at 17th level, your normally quick strikes and jabs meat to weaken your prey now hold the same killing power as your normal strikes, and you have learned to drain the very essence of your prey with each attack. You can now add an additional 2d6 damage to your melee weapon attacks, and whenever you hit your prey with a melee weapon attack, you can gain temporary hit points equal to the additional damage you rolled.

Additionally, while you have these temporary hit points, your speed increases by 30ft.