Soul Eater

Maka is a Meister and Soul is her Weapon. As students at the Grim Reaper's Death Weapon Meister Academy, their study habits couldn't be more different. But in battle against the supernatural forces of evil, they're a freakin' lethal team.
That's when Soul transforms - literally - into a razor-sharp scythe, and every defeated wicked soul he sucks down makes him more deadly. That's when Maka unleashes the merciless slayer within, wielding her partner and dropping monsters. Seriously. Monsters. Like the witches, werewolves, and zombies that lurk in the shadows and feed on the souls of the innocent. Every freakish ghoul Maka and Soul take out strengthens their bond, and fighting alongside their fellow Meister/Weapon classmates, Maka and Soul are the world's last line of defense against evil. (jakelijan virallinen teksti)