Your body no longer contains natural blood. Instead, a false heart created through necromancy and alchemy circulates an unstable artificial blood throughout your body. This alchemical fluid grants you unnatural vitality and allows you to exist somewhere between life and death.

Unlike true vampires, your hunger is not the result of a curse but of necessity. The artificial blood within you gradually loses its stability over time, requiring the consumption of fresh blood from living creatures to restore its potency. Without regular feeding, your body's condition steadily deteriorates, making it increasingly difficult to maintain your unnatural existence.

As your artificial blood becomes unstable, your body grows weaker and more vulnerable, especially under direct sunlight. The progression of these effects is described in the Blood Stability trait.

You do not age in the same way as ordinary humanoids, and your artificial blood cannot be fully restored through normal rest alone. Only the consumption of fresh blood can completely stabilize your artificial circulatory system.

Your artificial blood slowly deteriorates over time. To maintain your unnatural vitality, you must regularly consume the fresh blood of a living creature.

Track your Blood Stability using the following stages:

Stable (0–2 Days)

After consuming fresh blood from a living creature, your Blood Stability is restored to Stable. While Stable, you suffer no ill effects.

Unstable (2–7 Days)

If you have not consumed fresh blood for 2 days, your Blood Stability becomes Unstable.

While in direct sunlight:

• You have disadvantage on Wisdom (Perception) checks that rely on sight.
• You cannot benefit from resistance to radiant damage.

Critical (7–10 Days)

If you have not consumed fresh blood for 7 days, your Blood Stability becomes Critical.

While in direct sunlight:

• Your walking speed is reduced by 10 feet.
• You have disadvantage on attack rolls and ability checks.

Failing (10+ Days)

If you have not consumed fresh blood for 10 days, your Blood Stability begins to fail.

While in direct sunlight:

• You take radiant damage equal to your proficiency bonus at the start of each of your turns.
• You have disadvantage on attack rolls, ability checks, and saving throws.
• You cannot regain hit points by any means other than consuming fresh blood.

Consuming fresh blood from a living creature immediately restores your Blood Stability to the Stable stage.

At the center of your body beats a heart forged through a combination of alchemy, necromancy, and forbidden experimentation. Though artificial, it can temporarily force your body beyond its natural limits by accelerating the flow of your unstable blood.

As a bonus action, you can overdrive your False Heart for 1 minute. Once you use this trait, you can't use it again until you finish a Long Rest.

While your False Heart is overdriven, you gain the following benefits:

• Your walking speed increases by 10 feet.
• You have advantage on Strength and Dexterity ability checks.
• Once on each of your turns, when you hit with a weapon attack, you can deal additional damage equal to your Proficiency Bonus.

When the effect ends, your Blood Stability immediately worsens by one stage. If your Blood Stability is already at its lowest stage, you instead gain one level of Exhaustion.

Your artificial fangs are designed to pierce flesh and extract blood, allowing you to replenish your unstable artificial blood.

Your Bite is a natural weapon, which you can use to make unarmed strikes. When you hit with your Bite, it deals 1d4 piercing damage instead of the normal damage for an unarmed strike. You can use your Strength or Dexterity modifier (your choice) for the attack and damage rolls.

Once on each of your turns, when you deal damage with your Bite to a living creature that has blood, you may choose to feed upon it. The creature must not be a Construct or Undead.

When you successfully feed:

• You regain hit points equal to 1d4 + your Proficiency Bonus.
• Drinking enough fresh blood from a Small creature restores 1 day of your Blood Stability.
• Drinking enough fresh blood from a Medium or larger creature immediately restores your Blood Stability to the Stable stage.

To restore your Blood Stability, the creature must be willing, grappled, incapacitated, unconscious, or otherwise unable to resist, allowing you sufficient time to feed. A brief bite made during combat is enough to restore hit points, but not enough to fully stabilize your artificial blood.

Once a creature has restored your Blood Stability, its blood cannot stabilize you again for the next 7 days. Feeding from that creature during this time still restores hit points, but provides no further benefit toward your Blood Stability.

Your artificial eyes have been enhanced through necromantic and alchemical experimentation, granting you superior vision in darkness.

You can see in dim light within 60 feet of yourself as if it were bright light, and in darkness as if it were dim light. You discern colors in darkness only as shades of gray.

Unlike true vampires, sunlight does not destroy you outright. Instead, it reacts violently with the unstable alchemical blood flowing through your body.

While you are in direct sunlight, you suffer the effects determined by your current Blood Stability stage.

While your Blood Stability is Stable, sunlight causes no harmful effects beyond mild discomfort.

As your Blood Stability worsens, the effects of sunlight become increasingly severe, as described in the Blood Stability trait.

You are considered to be in direct sunlight only when exposed to natural sunlight without substantial cover. Shade, heavy clothing, magical darkness, or similar protection may lessen or negate these effects, at the DM's discretion.

You are an artificially created being, sustained by alchemical blood and a necromantic false heart rather than natural biology.

You count as a Humanoid for the purpose of spells and effects.

You do not need to eat or drink ordinary food or water, though you must still consume fresh blood to maintain your Blood Stability.

Your body does not age naturally after reaching physical maturity, though it can still be destroyed through violence or powerful magic.

Because your body is sustained by artificial blood rather than ordinary biology, effects that specifically target Undead do not affect you unless they also affect Humanoids.

Your false heart instinctively forces the last reserves of your unstable blood through your body when your condition becomes critical.

Whenever you roll initiative while your Blood Stability is Critical or Depleted, you gain temporary hit points equal to twice your Proficiency Bonus.

Once you gain temporary hit points from this trait, you can't do so again until you finish a Long Rest.

Necromantic magic is woven into every part of your artificial body, making you unusually resistant to effects that drain life force.

You have Resistance to Necrotic Damage.