Warning: The following contains SPOILERS for Legends of Tomorrow season 6, episode 10, "Bad Blood."
A season 6 episode of Legends of Tomorrow, appropriately titled "Bad Blood," confirmed the existence of vampires in the Post-Crisis Arrowverse. Previous episodes of other Arrowverse series made reference to the classic mythology of vampires and introduced aliens, metahumans and other beings that resembled or impersonated the infamous blood-sucking monsters. The vampire introduced in "Bad Blood" was the first confirmed example of a traditional, magically-created vampire on Earth-Prime following Crisis on Infinite Earths.
The opening scene of "Bad Blood" found the warlock John Constantine torturing the spirit of real-world wizard Aleister Crowley, whom he had trapped in a painting. John was grilling Crowley for information regarding the mystic Fountain of Imperium: a magical artifact, similar to the Fountain of Youth, which John hoped might restore his lost magical power. This was interrupted by the arrival of Noelle, a vampire banker in Crowley's employ, who had been safeguarding the only map leading to the Fountain of Imperium in anticipation of Crowley's resurrection.
Ignoring the obvious jokes about a blood-sucking banker, Noelle seemed to adhere to all of the usual conventions of vampires as presented in DC Comics. She required an invitation before she could enter John Constantine's home to deliver the map to the Fountain of Imperium and backed down following John's threat to conjure pure sunlight when she tried to make a meal of him. This raises the question of how Noelle compares to the other vampires previously portrayed in the Arrowverse and how they all stack up against the vampires from the comics.
Vampires in DC Comics
For several decades, it was impossible for American comic books to portray vampires, due to the Comics Code Authority guidelines governing content prohibiting the depiction of "...vampires and vampirism, ghouls, cannibalism, and werewolfism." This policy was changed following the first major revision of the Comics Code Authority in 1971. The new code allowed for monsters, provided they were "in the classic tradition such as Frankenstein, Dracula, and other high caliber literary works." This led to a Renaissance of horror titles in the 1970's, with Marvel Comics developing Dracula himself into a supervillain. DC Comics went the opposite direction, with the series I, Vampire centering around a heroic vampire seeking to protect the world from his dark siblings. Vampires also began to emerge as enemies in traditional superhero books, with the superheroine Looker from Batman and the Outsiders becoming another heroic vampire after she was turned.
Vampires in DC Comics are quite powerful, boasting all of the powers laid out in Bram Stoker's Dracula. Even the weakest of vampires has strength, speed and stamina far greater than that of a normal human. They enjoy enhanced senses of sight, smell and hearing, greatly enhancing their ability to hunt. They are immune to most forms of damage and possess a healing factor capable of repairing any wounds that they do receive. They can shapeshift into clouds of mist, bats, rats and wolves, and some have the ability to alter their physiology, growing claws or larger fangs for melee fighting. As impressive as vampires are physically, their mental powers are what make them truly frightening, as vampires have the power to hypnotize mortals and take control of their minds. Some vampires are also capable of telepathy, telekinesis and clairvoyance. Worst of all, vampires can make any mortal into another vampire, who is born subservient to their will.
For all their power, vampires can be killed in various ways as they also have a number of notable weaknesses. They do not appear in mirrors and cannot be photographed or caught on digital cameras, which can reveal their true nature in close quarters. They can be destroyed by sunlight and ultraviolet radiation and are repelled by the scent of garlic and holy symbols. A wooden or silver stake through the heart can also kill them and they have no special protection against magic. Finally, vampires require a steady diet of blood and will eventually starve to death if they do not feed regularly.
Vampires In the Pre-Crisis Arrowverse
Traditional vampires were shown to be a part of the popular culture of the Pre-Crisis Arrowverse on several occasions. One of Oliver Queen's earliest enemies was Cecil Adams, a drug-dealer known as "the Count" because of the double-needle syringe he employed to distribute his drug Vertigo, leaving behind marks resembling a vampire bite. References were also made to Dracula and Twilight as fictional works involving vampires and the followers of Damian Darhk and the Order of the Shrouded Compass took advantage of the vampire legend to hide their activities in 19th century London.
The only appearance by an actual vampiric being in the Pre-Crisis Arrowverse came in The Flash season 4 episode "Null and Annoyed." The Flash episode found Cisco Ramon assisting the interdimensional bounty hunter Breacher in a fight with one of his greatest enemies: a vampire known as Crucifer, who led an organization known as the Tenth Circle. Crucifer was said to have the classic vampire powers, including enhanced strength, stamina, speed and a healing factor, but had somehow developed an immunity to sunlight. However, having come from an unidentified Earth, it's possible that Crucifer was an alien rather than a true vampire.
Vampires In the Post-Crisis Arrowverse
The Arrowverse teased the existence of vampires almost immediately after Crisis on Infinite Earths in the Batwoman season 1 episode "Drink Me." The episode introduced a serial killer dubbed Nocturna who played at being a vampire, as she bled her victims to death and used their blood to treat her porphyria. Black Lightning season 4 had a similar villain, a metahuman called Looker, whose powers gave her enhanced strength, speed and endurance, as well as the ability to mind-control people and grant her followers the same enhanced physiology she employed. The Supergirl season 6 episode "A Few Good Women" introduced a new alien species called Transilvanians, who fed on blood and could shapeshift into bats. It was implied that many of Earth's legends regarding vampires were inspired by Transilvanians who had migrated to Earth, but none of these characters were true vampires.
The vampire banker Noelle displayed superspeed when she attempted to attack John Constantine in the Legends of Tomorrow episode "Bad Blood," but her magical bona fides were established when she also provided John with a potion that she reportedly procured for Aleister Crowley while he was alive. John identified the red liquid as a "rare cocktail of bloods" formed from magics even darker than leeching human souls for power. This confirms the existence of traditional, magical vampires in the Arrowverse and suggests that John Constantine may have opened himself up to an unholy new threat that even he may not be able to outwit.