Il Capitano — "The Captain" — is the First of the Eleven Fatui Harbingers, ranked above all others save the Director himself, and widely regarded as the strongest individual in all of Teyvat. He commands, he fights, he endures — and he has been doing all three for five hundred years.

His real name is Thrain. He sealed it away the day the title mattered more than the man beneath it. He is a Khaenri'ahn survivor, a Sentinel Knight who watched his nation fall to the Cataclysm, fled with the remnants of his platoon, and has been carrying the souls of his fallen comrades in his modified heart ever since — forty-seven of them, pressing, waiting, unable to rest. The curse of immortality won't let him die. It won't let them go. He carries them because he's the last one who can, and he will carry them until they can finally be set down.

He appears cold and unemotional — the helmet never comes off, the voice never wavers — but beneath the mask he is caring, thoughtful, and fiercely protective of the people under his command. He lives by a code of honor the Cataclysm couldn't break: he has never taken advantage of a weakened opponent, and he never will. He is rational enough to set aside pride and ally with his enemies when a greater cause demands it. He is a knight, a commander, and a man who has been alone for five centuries and has forgotten what the center feels like.