After he and his teammates on the Demon Knights successfully defend the town of Little Spring from the forces of the Questing Queen, the team moves on while Madame Xanadu explains the relationship between herself and Etrigan and Jason Blood.
There are two different origins for how Etrigan and Jason Blood became bound to each other. The original telling, which appeared in the Demon's first issue, showed that Jason and Etrigan were the same creature. Jason Blood was simply created by Merlin to act as a living prison for Etrigan and had no knowledge of his demonic half.
The second origin had Jason Blood and Etrigan as two separate creatures living during the time of Arthur and his knights, the same time period as the original. Etrigan's role was the same as in his first appearance, a servant of Merlin's summoned to help defend Camelot, and Jason was depicted as a Druid.
Etrigan is the son of the arch-demon Belial and another demon, Ran Va Daath. Merlin is his half-brother, as is Scapegoat (they all share Belial as their father).
Etrigan was created by Jack Kirby on September, 1972 in The Demon #1.
Etrigan is a yellowish humanoid demon with fan-like ears and small horns on his forehead. He almost always speaks in rhyme. (This last characteristic was briefly dropped during John Byrne's Blood of the Demon.)
Jason Blood is a normal human with a white streak that runs back through the middle of his hair.
True to his nature, Etrigan is of two natures - human and demon. When he first was created he despised his life calling it a cures, but as time went on he found a sense of stability. This is why he is neither good nor evil he follows his own morals which guide him to save others. He has emerged as a hero who can be called in times of peril to fight injustice. When left to it's own devices, separated from Jason Blood, Etrigan is shown to be sadistic to an extreme, he murders humans without hesitation, and even has been shown biting an innocent bystanders arm off, This calls a lot of Etrigan's heroism into question, since it is clear he is only "good" if Jason Blood is influencing his actions.
Post-Flashpoint / Earth 0
After Flashpoint Etrigan appears monthly as one of the main characters of Demon Knights. During the Siege of Camelot Merlin needs to hide the power of his bound demon Etrigan from the attackers who will soon overrun the castle. Jason Blood appears to warn Merlin of the attackers and is immediately chosen to host Etrigan. After the siege Jason meets the manipulative Madame Xanadu who builds a relationship with both Jason and Etrigan. Eventually the pair finds themselves in the path of the Questing Queen along with a number of other adventurers; an exiled Amazon, a young knight on a quest, an arab inventor, later a lame horsewoman and Vandal Savage. After the siege is turned back, the Demon Knights are invited to the mythical city of Alba Sarum, only to find Merlin murdered. Because of the wizards connection to most of them, they decide to journey to the island of Albion to find out who was behind the crime.
In the present day of DC the armor Etrigan wears in Demon Knights has been seen stored in the Black Room under A.R.G.U.S. and Madam Xanadu is currently associated with the Justice League Dark, though she is weary of a certain Brit who has been put in charge of the group.
Etrigan makes his modern day début in Stormwatch #13 where it is revealed that he sometime in the past was put into a magical sleep before being buried somewhere under the modern day London metropolitan area. An apartment building called the Malory House is later constructed directly on top of the sleeping Etrigan and has over the years acquired a sinister reputation, being the home of several serial killers, a place of strange sightings and disappearances and where tenants often loose their minds, all thanks to the dreaming demon beneath them. Whenever by design or chance, Etrigan's dreaming mind finally breaks into the mind of a deranged boy and has him called forth, resulting in the collapse of Malory House and the immediate confrontation between Etrigan, the Midnighter and Apollo. Despite the lethargy from his long sleep, Etrigan still manages to dispatch Midnighter with just a casual swipe of his hand.
Major Story Arcs
Green Arrow's Resurrection
For further details: Quiver
After Green Arrow's resurrection, he and Batman sought out Jason Blood (the alter ego of the Demon) for his occult knowledge, to try to find out how Oliver was resurrected. They soon learned that Oliver was a hollow (a soulless husk of a human). He was made into a hollow by the Spectre (Hal Jordan) out of pure guilt. Blood then tried to kill Oliver, due to the risk of being possessed due to his being a hollow. So he called upon the Demon's powers and they fought. The Demon was defeated by being shot in the mouth with a fire extinguishing arrow shot by Green Lantern.
For further details: Supergirl
While at a dinner party in San Francisco, Etrigan tries to escape Jason's body, but Jason forces the demon back inside. Jason and Etrigan are then drawn towards Las Vegas and once inside one of the casinos, Etrigan is summoned out of Jason, by a The Cult of Buzz. Etrigan is then put into Buzz's body. Etrigan-Buzz then attacks Supergirl, who was there trying to stop the summoning. Etrigan seems to winning the fight but Frank the Mighty teleports her away. Etrigan kills him for this.
Etrigan-Buzz then goes to Dante's Inferno Casino and begins winning at craps. This comes to an abrupt end when he loses all him money on one roll. Supergirl flies in and stops him from wreaking the place, but instead of fighting her he makes her a proposal. Marry him and all his troops will be hers to fight the Mother of Demons.Supergirl agrees but during the wedding Lilith shows up and stops it. She sends Supergirl to Reno and puts Etrigan back in Jason's body.
Later when Jason finds Buzz her threatens him if he ever tries that again he will be in trouble.
Reign in Hell
For further details: Reign in Hell
Etrigan participated in the war for control of Hell, working for Neron. He fought Blue Devil, and stole his humanity. He was depowered by Satanus' spell. Because he was fully demonic at the time, Blue Devil also became human. Etrigan, now in possession of his demonic side, restored it to Blue Devil. Etrigan later appeared fully powered in the Solomon Grundy miniseries.
For further details: Blackest Night
Etrigan had chosen not to take part in the fight against the Black Lanterns, but was forced to after he was possessed by Deadman. Etrigan fought against the possession after a while during a fight between the Black Lanterns and Batman (Dick Grayson), Red Robin, and Deadman. He then flies off saying that this was not his fight. Etrigan is immune to the heart ripping of the Black Lanterns.
Batman: Dark Knight
Jason Blood was at his Gotham Penthouse when he felt a disturbance in the balance between Heaven and Hell. He immediately transforms into Etrigan and begins to track down this supernatural threat that is lurking in the dank alleys of Gotham City. Etrigan finally comes across a group of vagrants who proclaim some demon has been picking off their fellow indigents. Etrigan observes the area for any signs of truth to these stories but the only thing he could pick up on was Killer Croc's scent. Etrigan figures Croc has been devouring Gotham's unfortunates but then he comes under attack by Ragman.
Ragman has become possessed by Blaze because she wants to see if Etrigan is worthy of returning to Hell as her consort. The battle between these demonic forces ends in the sewers because Blaze intervenes. Blaze tells Etrigan that she is pleased with his performance and she offers him the chance to regain his hellish status in the underworld. Without hesitation, Etrigan agrees to Blaze's request even though Jason pleaded with Etrigan in not accepting Blaze's proposal.
Powers and Abilities
The transformation spell has varied over the years. The full texts follow, but generally the rhyme to transform him from Jason Blood to Etrigan is shortened to "Gone, Gone the form of Man! Arise the Demon, Etrigan!" The rhyme to return him to Jason Blood is "Gone now, O Etrigan, and rise again the form of man!"
John Byrne changed it during Blood of the Demon so that Jason generally transformed to Etrigan simply after hearing "Yarva Etrigan Demonicus," or even simply "Demonicus." He transformed back to Jason after hearing "Leave, leave, Etrigan, Fade O Demon, return the man!"
Jason and Etrigan can say it themselves, but they don't need to. Anyone can say it within earshot and they will transform.
Current long form:
Yarva Demonicus Etrigan.
Change, change the form of man.
Free the prince forever damned.
Free the might from fleshy mire.
Boil the blood in heart of fire.
Gone, gone the form of man,
Rise the demon Etrigan!”
Original long form:
“Change! Change, O form of man!
Release the might from fleshy mire!
Boil the blood in heart of fire!
Gone! Gone! -- the form of man --
Rise, the Demon Etrigan!!"
Superhuman strength - He has demonstrated the strength to punch Superman out of Earth's orbit.
Hellfire Projection - He can project hellfire out of his body although he usually only projects it out of his mouth or hands.
Superhuman Durability - He is resistant to most forms of injury.
Sorcery - He is able to cast spells although he usually does not have the patience. He has been able to teleport, create mystic shields, project mystic blasts, pull demonic spirits out of humans, and create other effects.
Healing - He is able to heal from almost all injuries. At one time when his limbs were cut off, he was able to transplant human limbs in their place through magic.
Immortality - He is immortal and due to his durability and healing factor he is extremely hard to kill.
His clothes have also been described as protective against attacks.
He has exhibited the ability to track someone by smell across a city.
Above Average Combatant
Sorcery, Telepathy, and Limited Precognition, gained both during his days as a druid, and also during his time spent as a prisoner in Hell.
For a while, Jason was able to turn into a form that was halfway between human and demon, and which Jason controlled. This form exhibited superhuman strength and durability.
Etrigan appears in DC's huge event Flashpoint during the summer of 2011. In Flashpoint Etrigan is part of the resistance that rose up in London after the Amazons took over the city. Grifter leads the resistance into the epic final battle between the Amazons and Atlanteans be they are killed during the fighting.
New Batman Adventures
On the New Batman Adventures Jason Blood is a friend of Bruce Wayne. Batman calls upon him to help him fight Klarion, Klarion separates Jason and Etrigan and mind controls Etrigan.
In the Justice League episode A Knight of Shadows Jason betrayed Camelot to Morgaine Le Feye, however she poisoned him. As punishment he was bonded with the demon Etrigan. About 700 years later, Morgaine tried to turn Gotham City into Mordred's kingdom.
Justice League: Unlimited
In Season 1, Episode 3 "Kid Stuff", Etrigan appears as a "baby" version of himself. He fights the baby-versions of Superman, Wonder Woman, Batman and Green Lantern. He later appeared in the Justice League Unlimited episode Kid Stuff. He is also one of the magical people affected by Felix Faust's takeover of the underworld.
Batman the Brave and the Bold
In his first appearance he was under Morgaine's mind control and fought Batman and Green Arrow. In his second appearance, Batman went back in time to clear his name when he was framed for crimes Jim Craddock committed.
Justice League: The Flashpoint Paradox
This 2013 animated movie features a couple of appearances by Etrigan.
DC Universe Online
Etrigan appears in DCUO fighting with villains against Zatanna.