Jin appears during the opening portions of the game, initially planning to meet Hana to better brief on the upcoming job he's prepared -- to find and hold the daughter of Lam Wong hostage for ransom. However, Jin is captured and is then found with a bomb strapped to him. Hana manages to disarm it, but Jin is killed soon after by one of Lam's lieutenants. Some of his blood is splattered across Hana through the crossfire.
Jin will not appear until the very end, where he'll reveal himself to in fact be Yim Lau Wong: The King of Hell. He explains that it was because of his blood as to why Hana was resistant to the curse of Wee Ming Lam's blood that was turning everyone else into mindless zombies and monsters, acting as a premature vaccine granting her immunity.
Jin only plays a brief role during the opening cinematic, where he details Hana and Rain's latest heist. As this is also a prequel, all the knowledge towards Jin's true identity is still unbeknownst to Hana. Jin will make a couple of cameos nearing the end in his Yim Lau Wong form, but does not interact with any of the characters.