Blood of the Arch-Magi (artifact)
When Arch-Magi Kathalitos of the Mayikrata was found skewered on the chandelier of his study one cold morning in 1098, his assistant's first reaction was, against all reason and logic, to bottle up his blood. Kathalitos bled to death while he did so, and while dark magic was suspected nothing was ever proven. After his assistant disappeared soon after during the investigation, several of the vials would appear around the world decades later, the blood in the bottles still holding much power.