Umbra Witches (Bayonetta series) such as Bayonetta and Jeanne are capable of very powerful feats of dark magic through their connection to Infernal Demons.
Magus (Chrono Trigger) makes particular use of Black skills.
Manus, Father of the Abyss (Dark Souls: Artorias of the Abyss) is the first known user of Dark Sorceries, sometimes known as Hexes.
Nightshade (DC Comics) makes use of her dark magic from the Land of the Nightshades to act as a super heroine.
The Hive (Destiny) make great use of dark magic in their fight against the forces of the Traveler's Light.
Demon Hunters (Diablo series) make use of shadow magic in their hunt against the forces of the Burning Hells.
Empress Emily Kaldwin I (Dishonored 2) develops powers of the Void from the Outsider's Mark including the dark "Far Reach" and the transformative "Shadow Walk."
Freed Justine (Fairy Tail) making use of Absolute Shadow.
Kageyama (Fairy Tail) using Shadow Magic.
Mirajane Strauss (Fairy Tail) is capable of Darkness Magic through her "Satan Soul" spell.
Rogue Cheney (Fairy Tail), a user of Shadow Dragon Slayer Magic.
Ardyn Izunia (Final Fantasy XV) makes use of the Starscourge due to his intense daemonification, enabling him, unlike other humans, to use dark magic like daemons.
Rose Lalonde (Homestuck) while grimdark and channeling the power of the Horrorterrors.
Terra (Kingdom Hearts series) makes use of Darkness far more than Eraqus's other apprentices in his magic, to the point of it being a staple of his fighting style.
In his myriad forms, Xehanort (Kingdom Hearts series) made extensive use of Darkness in his quest for Kingdom Hearts.
As an inherently dark being by his very nature, Ganondorf (The Legend of Zelda series) is capable of using dark magic in his various incarnations.
Nico di Angelo (Percy Jackson and the Olympians/The Heroes of Olympus) has potent umbrakinesis on account of his divine parentage from Hades.
Dr. Facilier (The Princess and the Frog) had potent enough use of shadow magic through his voodoo that he was also known as the "Shadow Man."
Richard (Tales of Graces) has the primary elemental power of Dark artes, enabling him to use dark magic.
Sheena Fujibayashi (Tales of Symphonia/Tales of Symphonia: Dawn of the New World) is capable of using dark magic with her summon of Shadow's power.
Shadow Magician (Valkyrie Crusade)
Wizards of the Grey Order (Warhammer Fantasy) are known as "shadowmancers" for their use of the Grey Wind of Magic, also known as Ulgu, to manipulate darkness for illusions.
By the End Times, Malekith (Warhammer Fantasy) was the Incarnate of Shadow, possessing all of the power of the Grey Wind of Magic.
Among her many talents, Morathi (Warhammer Fantasy) is capable with Ulgu, the Grey Wind of Magic, and its use of darkness.
Alleria Windrunner (World of Warcraft) is the first being to master the power of the void's shadow magic without losing her sanity to it, making her the first of the void elves.
The Lich King (World of Warcraft) is very powerful with shadow magic, and capable of granting it to followers as well.
Pharaoh Atem (Yu Gi Oh) makes use of dark magic through the Millennium Items.
The Millennium Items (Yu Gi Oh) were created using Egyptian Black Magic and Alchemy, making them powerful artifacts of Dark Magic which is used in the Shadow Games.