The Armoury: Kurikara

Kurikara is a powerful demon sword used throughout Blue Exorcist, primarily by Rin. Originally the sword was forged in order to protect Kyoto from rampant spirits. Many years later after being used to vanquish the Impure King, the sword had Rin Okumura’s (the son of Satan) daemon heart infused into it, sealing away his powers until the sword was unsheathed.