Bloodfiends
Bloodfiends (혈귀, Hyeolgwi), are a unique type of Monster similar to Distortions that predate the White Nights and Dark Days, with a history that goes back for centuries.
They were formerly an obscure and esoteric phenomenon thanks to their secrecy and policing their own group, but the ascendance of the Blood-red Night to the status of Star of the City has since made them much more well-known, with there now being Fixers entirely dedicated to hunting down Bloodfiends.
They are directly inspired by vampires in modern literature, and much of their existence revolves around blood.
Overview
Bloodfiends have two major origins, the oldest of which being people who received blood in a "certain mansion"[1], possibly related to Nosferatu. These Bloodfiends have an intense hierarchy is based on the degrees of separation from their original progenitor whom created them. Despite not being related in the traditional sense, they refer to each other as family, and use familial terms. This "family" has settled into each Nest with their own territory, each with its own Elder, and "culled their kin" until they were able to live quiet lives[1]. However, Bloodfiends who defy this lifestyle still occasionally emerge, such as the Blood-red Night, whose actions eventually caused her to become a Star of the City.
Bloodfiends who arose from the Distortion Phenomenon also began to become common following the White Nights and Dark Days. These newborn, independent Bloodfiends lack any knowledge of the prior group's rules, and don't know how to control their powers, further increasing the infamy of the race as a whole.
Bloodfiends are nearly identical to ordinary people most of the time. The most obvious indicator is the black and red patterned crystalline growths that can appear during combat, usually on one half of the face. All Bloodfiends have red eyes; however, red eyes are not a surefire indicator of a Bloodfiend, as the color can be produced or modified through eye augmentations[1]. Additionally, people may not be consciously aware that they are Bloodfiends: Bloodfiend behavior may only emerge at night when they are sleeping, as in the case of one Fixer, Rusk [1], or under more specific conditions, as in the case of Don Quixote.
Bloodfiends are additionally defined by a persistent, but overally suppressible desire for blood, the accumulation of which acts as an euphoriant for them. Bloodfiends also need to "consume a minuscule amount of blood to maintain their forms"[2].
Bloodfiends and their Bloodbags appear to be constituted mostly of blood[3][4].
Abilities
Bloodfiends, as their name implies, gain much of their power through blood. By drinking blood, their physical abilities gain a sharp increase, though this increase can be drained away by injuring the Bloodfiend. There is no known limit to this increase beyond access to blood.
In addition, Bloodfiends have a large degree of control over blood, being able to shape it into weapons and armor by crystallization, as well as being able to draw it directly to themselves from their Bloodbags and Kindred. While most Bloodfiends seen use physical gestures to wield their blood-based powers, whether by necessity or as a simple flourish, Don Quixote shows that, at the very least, Bloodfiends of an early enough generation are able to do so while barely moving a finger.
By directly biting a living person, a Bloodfiend can either transform them into a Bloodbag, or, if they so choose, into a fellow Bloodfiend (a "Kindred"). It is also possible Bloodbags can be formed from fresh corpses by some Bloodfiends, as seen with the Blood-red Night from Library of Ruina.
Kindred
Kindred Bloodfiends essentially behave as independent Bloodfiends, while inheriting the abilities of their "Parent". However, Parent Bloodfiends have a large degree of control over the actions of Kindred or Kindred-generation Bloodfiends, enforced by a combination of Bloodfiend societal etiquette and physical ability to manipulate the Kindred.
While presumably any Kindred can form their own descendant Kindreds, it seems that Kindred management is very intertwined with Bloodfiend social practices and etiquette, as they need to presumably gain permission from their elders to form their own Kindred.
Bloodbags
Bloodbags are similar to Kindreds, having most of the abilities of normal Bloodfiends save that they do not display any sign of intelligence, instead being primarily driven by primal instincts and bloodlust. However, similar to Pallidified Things, skills acquired prior to Bloodbag conversion appears to be still extant, evidenced by Bloodbag Cleanup Agents and Prosthetic Fixers still using Charge-related Skills.
Due to their lack of intelligence, Parent Bloodfiends have a higher degree of control over Bloodbags than over Kindred, and thus usually use them as minions or tools in collecting blood.
Bloodfiends also appear to be able to puppeteer victims by manipulating the blood in their veins, rather than through the crystalline growths of blood seen with Cassetti.
Enemies
Cassetti's Kindred
For more combat information about Cassetti's subordinates, see Cassetti's Kindred.
Bloodbags created by Cassetti can be divided into three major categories: the Bloodbag Passengers, the Bloodbag Cleanup Agents, and the Bloodbag Prosthetic Fixers.
All three categories of Bloodbags have Skills that focuses on the application of 
Bleed Bleed
The next Y time(s) this unit tosses an attack skill Coin, take X fixed damage., with the Bloodbag Cleanup Agents and Prosthetic Fixers also utilizing 
Charge Charge
Resource used by certain skills for additional effects. Its Count can go up to 20. Count lowers by 1 at the end of each turn. buildup and release, similarly to their respective factions prior to Bloodbag conversion. All Bloodbags converted by Cassetti also take reduced damage from Bleed Bleed
The next Y time(s) this unit tosses an attack skill Coin, take X fixed damage., and gains Bleed Bleed
The next Y time(s) this unit tosses an attack skill Coin, take X fixed damage. Count on self when hit, which they then convert to 
Coagulated Blood Coagulated Blood
Gain Offense Level and Defense Level equal to the value (max 5) on Turn End.
Known Bloodfiends
Limbus Company
- Don Quixote (Second Generation Bloodfiend)
- Cassetti (Sixth Generation Bloodfiend)
- Sasha (Cassetti's Kindred)
The Distortion Detective
- Larierre (L Corp. Elder)
- Rusk
Library of Ruina
- Elena (Blood-red Night)
- Nosferatu An Abnormality typically assumed to be the original Bloodfiend, or otherwise significant to their origins
References
- ↑ 1.0 1.1 1.2 1.3 Distortion Detective Chapter 42
- ↑ 6.5-23: Bloodfiends
- ↑ 6.5-22: Painting of Hell 2 - Ryōshū: "I smelled blood, so that's likely what they're made of."
- ↑ 6.5-29: The Negotiation - "Cassetti's body begins liquefying into a slick stream of blood, his form curdling and crumbling, then dripping to the ground."
I Corp. - 
