Death Weapon Meister Academy
The Plotline (we're pretending is canon)
Somewhere between the plot of the manga and the anime, a crude overview is that the plot of the anime is mostly completely followed, but Soul and Maka kill Arachne, resulting in Soul becoming a Death Scythe, Death does not move from his place, cannot fight Asura a second time, and does not die, but is mostly drained of all power when Kid finally completes his three Sanzu lines, and Kid does take over, after Asura is sealed permanently on the Moon by Crona's sacrifice (to be absorbed by the black blood and eventually lose all power or consciousness). Once Kid takes over, they form a truce with witches, where Death Scythes are only made from the souls of witches sentenced by their society to permanently die (so long as the Meisters can defeat them in fair combat). In this version, Maka is also both a weapon and a meister, though she does not become a Death Scythe or become a weapon unconsciously.
Witches and Sorcerers
Witches and sorcerers are magical beings who look like regular humans. They are incredibly long-lived and often naturally quite powerful, but very few of them exist. Witches are animal-themed, while sorcerers do not seem to be, and instead more often use Demon Books as part of their magic, seeming more intellectual, in a way. Very little is known about how they come to be or how long they have existed. In fact, while witches keep their separate societies and sorcerers are largely solitary, they may sort of be the same species, as witches and sorcerers can only be born from the union of a witch and a sorcerer, with girls becoming witches, and boys becoming sorcerers. Witches are born with their animal elements, but are rarely born with an animal theme already possessed by a currently-alive witch. Both witches and sorcerers can have children with regular humans and Demon Weapons, but these half-witch or half-sorcerer children are perfectly normal humans (if more likely to have unusually strong souls). Worse, witches and sorcerers are notorious for not caring at all for their children, magical or otherwise.