Altaïr's Hidden Blade

Origin
Eizo Auditore is one of the central characters in the Assassin's Creed Franchise, having starred in more games than any other Assassin. This prop synced itself with the love and attention of the series' fandom.

Effects
Strapping the artifact to the user's forearm induces and boosts a masterful skill in parkour and free-running, which entails navigating an environment (typically urban) by running, climbing, jumping and rolling, with the latter adding acrobatics into the art.

However, the wearer may suffer what's known in the fandom as a "Bleeding Effect", where the person's genetic past begins to leak into their present. This includes forgetting what year it is, leading to delusions, hallucinations which increase in severity, Dissociative Personality Disorder, and possibly death from the sheer mental stress.

Collection
Agents Aden Taylor and Pete Lattimer, accompanied by Soul Blake, encountered this artifact being worn by a young man cosplaying as the video game character Eizo Auditore da Firenze, while on a mission to collect Hunter's Hoodie. Aden convinced the fan to surrender the artifact by winning a free-running race across Boston, Massachusetts.