The Blood Frenzy

"Blood Elves are a cursed people. I don't know where the curse came from, but it is potent. I can't dispel it to save my life, and that's saying something. Under interrogation, they'll tell you it's from an old sin, but vagaries like that don't help anyone. Regardless, it's a mystery, one that may never be unraveled. I do have my theories, but for now, best to put the blood elves down when you find them, before they start bleeding."
~Archmage Dulacar
Rach Agarwaen - The defining feature from which the Blood Elves derive their names, the Blood Frenzy is a potent curse of mysterious origin. There is no known means of dispelling it; there is only avoidance and appeasement.
Undead, constructs, slimes, plants, and other creatures without blood cannot be the targets of the Blood Frenzy, even on a successful redirect save.
While frenzied, the Blood Elf has the following effects: -The current target of their rage cannot regain hit points, and must roll a Wisdom (fear) save each round or they lose their bonus action. -At the beginning of their turn, the Blood Elf loses 1d6 HP. -Every successful attack does an extra +5 necrotic damage. The Blood Elf regains the amount of damage dealt this way at the end of their turn.

Transmission & Vectors

Every blood elf is born with this curse, though it typically doesn't actually manifest until adulthood.

Symptoms

The curse manifests when the Blood Elf witnesses, receives, or causes 5 damage or more of slashing or piercing damage, or when their health drops to half of their maximum. When they enter the Blood Frenzy state, a terrible change occurs. They can no longer distinguish friend from foe. Instead, the Blood Elf must roll a Wisdom Save DC 8 + the amount of unhealed damage they have received or they will close with and attack the creature within 60 ft. that has received the most piercing or slashing damage. Every round they can roll another Wisdom Save as a bonus action to regain control and either end the rage or redirect it, but barring a successful save they will attack the target of their frenzy to the exclusion of all other concerns including self-preservation and childhood friendships. If no save occurs, the rage ends when the current target has expired, at which point the Blood Elf will tear into it with their teeth and hands to ingest as much blood as they can hold. When they have had their fill (One full round action of drinking), the rage ends.
When they enter the Blood Frenzy, they begin to bleed out of their noses, mouths, ears, and eyes. The blood runs down their face to form a bloody mask before evaporating in a faint halo of crimson mist. This mist flows towards the object of their rage, forming a mystic connection with their soon to be victim. Their mouth hangs open in an uncontrolled bestial scream that seemingly requires no intake of breath, their face is a bestial mask of blood and hatred. Their flesh collapses inward slightly, and they appear gaunt and emaciated. Under normal circumstances, they have a clear and vivid memory of what occurred. In many cases these moments of rage feel more like reality than the rest of their lives, and more than one Blood Elf has been lost to the rage seeking this high.
As a final effect of the curse, the Blood Elf is haunted at night by victims of their rage. To gain the benefits of meditation, they must roll a Wisdom Save DC 6 + 1 for every life they have taken in the Blood Frenzy over the long course of their lives. On a failure, they spend the night thrashing and screaming as the shades of their victims attack them in their dreams. They do not gain the benefits of their meditation, and on a critical failure they gain a level of exhaustion until they successfully sleep.

Treatment

The nightmares don't arrive on a day that the Blood Frenzy has been satisfied by killing another creature and drinking its blood. Other than that, there are potions, herbs, and spells that have been known to boost willpower that are sometimes used to attempt to gain control over the curse.

Prognosis

If the blood elf avoids all violence and never indulges their frenzy, they might live a long and sane life.
More likely, they will be battling with insanity for the latter half of their lives, and if they aren't killed in battle then they are driven entirely made or exhausted to death by the lack of good rest.
One in fifty blood elves lives a soldier's life and dies of old age.

Sequela

The lack of sleep can cause exhaustion and death or insanity.
The power and furious joy of the frenzy can be addictive, and reckless behavior can result.
The carrots and sticks are aligned for blood elves to become serial killers, if for no other reason than to get an occasional night's sleep.

Cultural Reception

Due to this condition, Blood Elves are avoided by other elves. To Elvenkind, slaying another elf is the highest sin, but the Blood Frenzy plays no favorites. Wood elves counting coup who wound a blood elves may find themselves fighting for their lives.

Type

Magical

Origin

Magical

Cycle

Chronic, Congenital