The Azoth Sword is a legendary weapon said to house Beelzebub. It is held by Marcus Lithos.
The Azoth Sword is a silver blade with a large pommel, hilt and guard. The pommel itself is said to be a philosophers stone, in which there is a trapped demon.
In the 16th Century, an alchemist named Paracelsus made a deal with a demon. In exchange for mastering alchemy, he would sell his soul. With this knowledge, Paracelsus made the philosophers stone. But then, he broke the contract. In response the demon attacked him, but Paracelsus managed to emerge victorious by sealing the demon in the Philosophers stone in the pommel of the weapon.
Paracelsus is an alchemist who originally sealed the demon in the sword.