Madame Xanadu was created for DC Comics by writer David Michelinie and artist Val Mayerik in 1978, initially serving as a linking character in anthology series Doorway to Nightmare, a 'good witch' who'd help people out with their supernatural difficulties. She went on to join Jim Corrigan's Spectre as part of his supporting cast, and pops up from time to time in DC's other magic-based books.
She had a Vertigo series from 2008-2010, written by Matt Wagner and penciled mainly by Amy Reeder Hadley. The series runs with the revelation in Neil Gaiman's original The Books of Magic series that Madame Xanadu was Nimue and reveals her to be the youngest sister of Morgana Le Fay and the Lady in the Lake, an immortal who has lived for thousands of years. It chronicles Madame Xanadu from her prehistoric childhood, through Arthurian times, up through the 1960s.
In the New 52, she was a main character in Demon Knights (set in The Dark Ages) 2011-2013, an occasional character in Resurrection Man 2011-2012 and was a founding member of Justice League Dark, although she's currently only a supporting character.
- The Apprentice: Charlotte Blackwood.
- The Atoner: The main reason Xanadu established herself as a minor heroine dealing with arcane problems is to repent from the guilt of allowing Jim Corrigan to die, resulting in a new host for the Spectre and his onslaught of vengeance from that point on.
- Been There, Shaped History: Wandering the earth for centuries, she acquainted herself with many great historical figures and acted as their advisers. She picked up the sobriquet "Madame Xanadu" after spending time in Kublai Khan's court at Xanadu as his adviser and attempted to advise Marie Antoinette as her honored guest as Versailles during the The French Revolution.
- Bi the Way: Xanadu's romantic tastes have varied over the centuries and she has been in close intimate relationships with women and men.
- Burn the Witch!: Marisol, Xanadu's lesbian lover, was burnt as a witch by the Spanish Inquisition.
- Cain and Abel: Morgana/Morgaine le Fey is the Cain to Nimue/Madame Xanadu's Abel .
- Chess with Death: With her Tarot cards, Madame Xanadu convinced Death to restore her power and immortality.
- Collector of the Strange: Her parlor is full of magical books and objects she's collected over the centuries.
- Continuity Nod: Despite being Vertigo, there's a heck of a lot of references to The DCU. Madame Xanadu is the sister of JLA villain Morgaine le Fey, witnesses the summoning of Etrigan, is indirectly responsible for the origin of Doctor Fate and the Golden Age Green Lantern, and nearly prevents the origin of Jim Corrigan's Spectre, while living with Giovanni Zatara. Not to mention The Phantom Stranger. Or her teamup with the Martian Manhunter.
- It's actually less that she's indirectly responsible, and more that she keeps getting mixed up with the Phantom Stranger's various schemes to ensure they happen, while sometimes ending up being a pawn to that end (as in the case of the original Green Lantern).
- Crystal Ball: She uses ones to observe events from afar.
- Did You Just Scam Cthulhu?: She gained absolute immortality by besting Death in a card game. Her immortality extends to the point even the Spectre cannot kill her, only maim her eternally.
- Deal with the Devil: She tried to cheat Neron by ensuring he would only get her soul if she were to die, counting on her immortality. However, Neron had the last laugh on her when he increased her power by giving her three loyal demons, which acted on her slightest passing thought. He also allowed it even if he saw it coming to prove he could corrupt anyone, even more morally upstanding citizens like her. In the end, she was forced to learn to dominate herself and gain more control over the demons.
- Does Not Like Shoes: In the 2008 series, she's more often than not barefoot.
- De-Power / Re-Power: After the Fall of Camelot, Merlin stripped her of her innate magic, requiring additional potions to remain immortal. A tiny bit of her power was restored after a brief contact with a brilliant green lamp in the court of Kublai Khan, and she was able to bargain with Death of the Endless to restore her original immortality. Nevertheless, she remains much, much weaker than she was initially, and has been known to seek means to increase her power.
- Eye Scream: The Spectre was unable to kill her during his rampage against magic in Infinite Crisis, but seared her eyes in an attempt to block her from using her favorite divination method, the Tarot. In the end, she was assisted in her lectures by an apprentice. To make it worse, her immortality still tries to regrow her eyes, only to have them seared once more once they're finished. By the time she's consulted, she has regrown and lost her eyes fourteen times.
- The '50s: The setting of Broken House of Cards.
- Fortune Teller: Her whole wheelhouse.
- Friend to All Living Things: Xanadu, though she has a nasty petty streak which can make her act pretty horrible at times.
- Hot Gypsy Woman: She plays up the appearance of the sexy Gypsy archetype but it's vague if she actually is one or even Romani considering her background.
- Idiosyncratic Episode Naming: Each chapter in the first storyline is titled by a form of divination, which Madame X uses in that chapter: "By the Runes", "Among the Stars", "In the Cards", "Thru the Crystal", and finally the more general "Of the Future".
- Julius Beethoven da Vinci: She was the Nimue in Arthurian Lore, once known as Nimue Inwudu and the youngest sister of Morgana (to become Morgaine Le Fay) and Vivienne, the Lady of the Lake, who cast an imprisoning spell on her former lover and teacher Merlin. She blamed him for manipulating Camelot, King Arthur, and the course of history for his own gain and tried to seal him away as part of a prophecy but it backfired.
- Madame Fortune: It's right there in the title.
- Merlin and Nimue: Xanadu was Nimue, and betrayed Merlin because she believed it was the only way to save Camelot. It doesn't work.
- My God, What Have I Done?: In a petty bid to annoy the Stranger (which also destroys her relationship with Giovanni Zatara), she allows a cop to die at the hands of the mob. When she forces herself to go to the place where the gangsters disposed of the corpse, she's horrified to realize her choice has resulted in the latest incarnation of the Spirit of Vengeance, the Spectre.
- Occult Detective: Despite not doing much detective work, she works as an information broker and informant for occult detectives in the magic community.
- Psychic Powers
- The '60s: Setting for Extra-Sensory.
- The Spanish Inquisition: One of her adventures, where she meets the original Sandman, deals with a demon contracted by the Inquisition to destroy several bloodlines and her own reminiscences of the death in the pyre of one of her lovers at the height of religious hysteria in Spain.
- Tailor-Made Prison: She contains dangerous supernatural entities in mason jars to prevent them from causing further trouble.
- Tarot Motifs: Madame Xanadu created the Tarot herself.
- Tarot Troubles: Her fortune telling tends to be vague, unclear, or just plain unhelpful due to the the obscure meaning behind her card results.
- Teleporters and Transporters: Madame Xanadu has the ability to "disapparate." Interestingly, she can't fly, and her sister Morgana can fly but not teleport.
- The Vamp: She's played this card since the beginning as Nimue to Merlin and has been doing so for centuries onward. She even at one point managed to seduce John Zatara, Zatanna's father, into sealing away the Phantom Stranger out of spite and even managed to have a sexual relationship with the Spectre of all beings to strip away its power for her own agenda.
- Well-Intentioned Extremist: At her worst, she becomes one of these such as when she stole the Spectre's power and tried to use it to remake the world according to her wishes of female dominance as revenge for years of misogyny among mankind and restoring nature. Her first act was castrating an abusive pimp and murdering CEO's of polluting companies instead of actually solving any problems she mentioned.
- Witch Species: She is of the Elder Folk, ancestors of the Homo Magi, but lost her ability to use magic as a last laugh by Merlin for sealing him away.