"Though some might say there is not much point to turning the earth into one gigantic graveyard, these people are fools and will never understand anyway."
― Neil Zawacki, How to be a Villain
"The dead make good soldiers. They can't disobey orders, never surrender, and don't stop fighting when a random body part falls off."
― Nevinyrral, "Necromancer's Handbook", Magic: The Gathering
The power to utilize magic involving the dead, death-force and/or souls. Form of Magic. Opposite to Animancy. Practitioners of this trade are known as Necromancers.
The user's magical abilities revolve around manipulating the dead, death, the death-force and/or souls for good (i.e., resurrecting the dead), evil (in various ways) or neither. They can also communicate with the deceased – either by summoning their spirit as an apparition or raising them bodily – for the purpose of divination, imparting the means to foretell future events or discover hidden knowledge.
Many practitioners find a way to cheat death one way or another, whether by becoming some form of undead creature or by bypassing their own ability to die.
Keith (Fairy Tail) is revealed to be a Necromancer.
Merascylla (Nanatsu no Taizai) can raise the dead with their rage and spite powering them.
So'unga (Inuyasha) is a demon sword with tremendous necromantic powers, allowing the reanimation of hundreds of dead souls and open a massive portal to the netherworld that can absorb the entire world.
Ainz Ooal Gown (Overlord)
Eri Nakamura (Arifureta Shokugyou de Sekaisaikyou) is a genius necromancer, who can reanimate hundreds of corpses and interface directly with the souls of the dead.
As one of the few wields of death-attribute magic, Vandalieu (The Death Mage Who Doesn't Want a Fourth Time) can take the soul of any being and use it to reanimate the dead or create Golems, Cursed Weapons or Living Armour.
Nicknamed the Boneyard Sorcerer, Johann Faust VIII (Shaman King) is a highly skilled Shaman specializing in Necromancy, able to reanimate not only his Guardian Ghost but also control an entire army of skeletons.
As a Shadow Monarch, Sung Jin-Woo (Solo Leveling) can create shadow soldiers from the dead to serve him. Also, he can store a limited amount of shadows.
Necronomicon Ex-Mortis (Evil Dead), the Book of the Dead.
Through a pact she made with Set, Ahmanet (Dark Universe) gained tremendous power over necromancy, able to reanimate herself as an undead, mummify people and even reanimate dead corpses that abide by her will.