OVA
Description
Kilian Black hails from the forbidden planet Herise, where his biological parents perished saving him during the planet's annihilation, provoking devastating retaliation from unknown enforcers. Rescued as an infant, he was adopted and named by the Conductor of the Galaxy Express 999.

His origins surface in the OVA "A Letter from the Abandoned Planet" when the Galaxy Express 999 crashes on Herise, prompting a Sirius Platoon mission from the Space Defence Force. The derelict train triggers Kilian's intense resolve, driving his actions throughout the OVA and exposing his link to the forsaken world.

In the sequel series "Crossroads to Eternity," Kilian becomes a Sirius Platoon intern trainee under Manabu Yuuki's mentorship. His training echoes Bruce's harsh methods with Manabu, casting Kilian as the platoon's next-generation successor. Kind and earnest by nature, he grows severe when confronting events like the 999's wreckage. An implied romantic inclination toward crewmate Louise remains secondary to his duties.

During a crisis near Tabito, Kilian aids in tracking a runaway train emerging from a dimensional fault, showcasing technical aptitude. His role evolves as the Sirius Platoon ventures into an alternate universe, though specific deeds there remain undocumented. Kilian ultimately solidifies his place as a committed Sirius Platoon member, embodying their perseverance and duty.