Liu Pengli's Hanfu Hat

Origin
Liu Pengli (2nd-century BC) was a Han prince and one of the earliest serial killers attested by historical sources. As young as twenty nine Pengli would go out on marauding expeditions with tens of slaves or other young men. They would murder random people and seize their belongings for sheer sport. Confirmed victims exceed one hundred and they weren't a secret, being well known throughout the kingdom. Eventually the Emperor, his uncle, was informed but instead of executing the prince he was stripped of power and banished.

Effects
Wearing for as little as five minutes warps wearers minds, turns normal people into wrathful serial killers.