Very awesome fusion and love the idea!
Possible Origin Story(?): Zatanna Maximoff was born to a nomadic Romani witch named Natalya near Novi Pazar, in Serbia. Unknown to anyone but Zatanna when a newborn was imbued with the mystic energies of the Wundagore Mountain, which was in fact a prison for the demon-lord of chaos known as Chthon. From that moment on, she acquired a natural latent talent for the practice of magic. Afraid of harming her child due to her perilous lifestyle, Natalya Maximof placed the babies under the care of her brother, John Zatara. The famed magician Giovanni "John" Zatara took care of Zatanna as now Zatanna was a successful stage illusionist herself before she discovered her true magical powers. She was once in a relationship with the powerful mage Nick Necros in New York City. (John Constantine x Any Marvel character) came to the city to study under Nick, who became obsessed with the search for the Books of Magic. As a result of his obsession, (John Constantine x Any Marvel Character) and Zatanna were alienated from him, and fell in love with each other. Nick felt betrayed, and tried to have them both killed by the Cult of the Cold Flame. Fortunately, they turned the tables, and his soul was sent to hell. Eventually, though, (John Constantine x Any Marvel Character) characteristically broke her heart. Their relationship was further strained by the fact that one of his schemes intended to save the world resulted in her father's burning to death before her eyes. Zatanna's potential for magic eventually attracted the attention of a powerful coven formed by Margali Szardos, Maria Russoff, and Lilia Calderu. Calderu approached Zatanna's mom and had her bring Zatanna to Castle Russoff. They hoped to recruit Zatanna into their coven as an apprentice, being able to predict her future as a relevant magic wielder. However, servants of Chthon, Taboo and Damballah, interfered with Zatanna's initiation. The battle only ended once Zatanna was able to manifest her hex powers for the first time, accidentally allowing Chthon to reach out to her soul and make it known that Zatanna was not allowed to join any coven. Zatanna soon found out that she is the direct descendant of the artist and magician Leonardo da Vinci, and is related to Nostradamus, Alessandro Cagliostro, the noted alchemists Nicholas Flamel and Evan Fulcanelli and Lord Arion of Atlantis. Zatanna accidentally set fire to an unnamed village with her powers, and was attacked by villagers. One of them proclaimed her to be "a Ebony Witch," which would later become her codename. (Magneto x Any DC character) arrived at the scene, and rescued Zatanna from the villagers. Due to this rescue, Zatanna felt indebted to (Magneto x Any DC character). She was willing to serve him until her debt was repaid. Zatanna was later recruited into (Magneto x Any DC character)'s (Brotherhood of Evil Mutants x Any DC group). As the Ebony Witch the fought the X-Titans (X-Men x Teen Titans) on several occasions. But Zatanna soon left the group and went on her own adventures where Zatanna then continued her career as a stage magician and not much later, she met other notable heroes such as Silver Flash (Quicksilver and The Flash), Thunder Girl (Jane Foster x Supergirl) and Green Hawk (Green Arrow x Hawkeye). She then soon joined the Justice Avengers as a magical support.