OVA
Description
Originally named Reiji Azuma, he was an ordinary Japanese tourist visiting Los Angeles when he witnessed an assassination by the Inferno organization. His evasion of capture by their top assassin, Ein, revealed exceptional survival instincts that impressed their leader, Scythe Master. Consequently, Inferno kidnapped him, erased his memories through drugs and hypnotherapy, and presented an ultimatum: join as an assassin or die. Choosing to join, he received the codename "Zwei," signifying his status as the second experimental assassin created by Scythe Master.

Ein trained Zwei in firearms proficiency, hand-to-hand combat, knife skills, and assassination techniques. His training culminated in a test mission to assassinate Navy SEAL Lieutenant Wallace. During this mission, a near-death experience fully awakened Zwei's lethal capabilities, marking his acceptance of the "Zwei" persona. He subsequently partnered with Ein on assignments, including the assassination of mafia boss Don Muchio and the elimination of Tony Stone's family—Eva Stone and Duke Stone—under orders to psychologically break Tony.

Inferno executive Claudia McCunnen later triggered an identity crisis by revealing Zwei's original identity, returning his pre-brainwashing passport identifying him as Reiji Azuma. When Ein was severely injured on a mission, Reiji rejected the "Zwei" persona, rescued her, and fled Inferno. He renamed her "Eren," vowing to protect her and build a normal life. Their refuge in Japan proved short-lived as Inferno tracked them down. During the confrontation with Scythe Master, Eren sacrificed herself, taking a fatal bullet intended for him. Scythe Master then shot Reiji, who fell into the ocean. He resurfaced three months later as the new "Phantom of Inferno," the title denoting Inferno's top assassin.

Zwei mastered sharpshooting under adverse conditions, achieved expert-level hand-to-hand combat capable of defeating Ein, and possessed heightened survival instincts. His appearance featured brown hair and eyes, though his eyes shifted to green with orange centers when exhibiting killing intent. His attire evolved from casual clothing to formal suits as he became entrenched in Inferno.

A significant subplot involved his relationship with Cal Devens, a girl seeking vengeance for her adoptive sister Judy's murder. Reiji took Cal under his protection, promising never to abandon her. However, after fleeing to Japan with Eren, Cal believed he betrayed her. Brainwashed by Scythe Master into becoming the assassin "Drei" and inheriting the Phantom title, her hatred drove her to relentlessly hunt Reiji, unaware he believed she died in an explosion.