Shinjuku no Assassin

Qing Yan is a member of the Phantom Demon Alliance, fused with the Phantom Doppelganger through the machinations of Baal. Before Chaldea's arrival, he killed Hassan of the Cursed Arm. Disguised as Cursed Arm, Qing Yan arrives in Kabukicho after the Phantom and Christine have been killed. He stops EMIYA Alter from killing Ritsuka and James Moriarty, and convinces him to retreat. Afterwards, he returns with Ritsuka's party back to their hideout. Qing Yan reveals the Alliance's objective is to destroy the planet, then "hears" someone skulking nearby and takes Ritsuka outside to look. There he removes his disguised and takes Ritsuka hostage. (Chapter 16)