Soul Eater, anyone~?

At the start of Soul Eater, Maka and Soul encounter the meister Crona and Crona's weapon Ragnarok; Crona is being forced to attack non-evil humans by Crona's mother and witch Medusa. Medusa eventually recruits the witches Eruka and Mizune, along with the immortal werewolf Free.
Medusa and her cohorts attack DWMA on the eve of the festival to
commemorate the establishment of DWMA. Medusa's goal is to revive the
first "kishin" (鬼神^?), an evil demon god that nearly destroyed everything by plunging the world into madness, named Asura
who was sealed beneath the DWMA by Shinigami. Medusa's group
successfully revives Asura, though Medusa is seemingly killed in the
process.
As Asura escapes the DWMA, the world is plunged into chaos and insanity, and because of this, Medusa's older sister Arachne
comes out of hiding after 800 years. Arachne reforms her organization
Arachnophobia, which poses itself as a serious threat to the DWMA;
Arachne is joined closely by her demon butler Mosquito and demon weapon Giricco. The DWMA calls in the Death Scythes Justin Law, Yumi Azusa, and Marie Mjölnir
to aide in the fight against Arachnophobia. During this time, Medusa is
proven to be alive and possesses a young girl named Rachel. Maka and
the other students are progressively getting stronger as they train and
participate in various battles. Medusa makes a truce with the DWMA for
a time so together they can annihilate the threat of Arachnophobia.