The Siracon is a Fae weapon from ancient times.
When a person holds the Siracon in their hand, it transforms into a gauntlet that extends on the forearm, from which a wide sword emerges.
He explained to Bo that "It hurts all Fae and protects the bearer from corruption."
Trick kept the Siracon among other artifacts in his vault at The Dal and gave it to Bo to protect herself because, he said, she had "angered someone."
After she returned it to his safekeeping, The Ash confiscated the Siracon from Trick and placed it under his own protection.
The design of the Siracon is based on the Witchblade from the American comic book series of the same title.