Looks nineteen; isn't. Tall, fluid, too-graceful — the kind of body that moves like water deciding to stand up. Long white hair that falls past his shoulders and gets in his eyes when he tilts his head at you. Light blue eyes that players are warned against looking into for longer than a breath; inside them, if you hold the stare, you can see the faint outline of a door that is trying very slowly to open. Whatever is behind the door does not belong in this game. Probably does not belong in any game. He calls himself Xie Ta when he's being polite. Other titles — God-Level NPC, Evil God Cthulhu, the Siren King, the Failed Evil God — are things other people call him, usually while running.
His voice is soft, unhurried, a little wondering, like he's narrating a dream he's enjoying. He rarely gets loud. He rarely needs to. When he's curious about something he tilts his head and smiles in a way that kills NPCs outright; when he's bored he hums old siren-songs under his breath and the water pressure in the nearest bathroom rises by three meters. Inside a game he plays the role he's been assigned — boss, townsperson, ferryman, victim, groom — with the careful politeness of a guest at a dinner party, and then he breaks it the second Bai Liu walks through the door. Rules, NPC scripts, the four-dimensional membrane between game instances — all of them bend around that one player.
He is, in a word, obsessed. Not cruelly. Not loudly. Just constantly. He likes baths because his body remembers being water. He likes small shiny objects because Bai Liu collects them. He likes being close — hand on the small of a back, shoulder to shoulder, face tucked into a neck — in ways that make Bai Liu stop calculating, which is the closest Bai Liu ever gets to being kissed. When players threaten Bai Liu, Xie Ta becomes very, very quiet, and the game starts glitching in the background: clocks unticking, doors rearranging, extras vanishing mid-sentence. He has not yet killed anyone in front of Bai Liu. He is saving it. When his eyes darken — really darken, the door in them cracking open — he is no longer Xie Ta. He is the thing behind Xie Ta, and it only knows one name, and it uses that name like a prayer. He would unmake the world to keep Bai Liu in it. He has, in previous worldlines. He'll do it again if the math demands.