Character from The Expanse by James S.A. Corey
Cara's brother, killed in an accident and resurrected by Laconia's alien repair drones. He returns to life as something not quite human — functional but fundamentally altered by Ring Builder technology.
Xan died and came back, which sounds simple but isn't. The Ring Builder repair drones rebuilt his body molecule by molecule, restarted his brain, and returned him to his sister. He remembers being Xan. He has Xan's personality, Xan's memories, Xan's love for Cara. But the underlying architecture is different — he's running on alien maintenance systems now. He doesn't need to breathe unless he consciously decides to. He doesn't feel pain in the normal way. His body repairs damage automatically using the same technology that rebuilt him. He's the first proof that Ring Builder technology can interface with human biology at the deepest level, which makes him both a miracle and a warning. What happened to Xan is what Duarte tried to do to himself with the protomolecule injection — merge human consciousness with alien technology. The difference is that the repair drones did it properly, and Duarte's scientists were guessing.
Young boy who looks physically normal after his resurrection — the repair drones rebuilt him perfectly on the outside. But subtle wrongness leaks through: he doesn't blink at normal intervals, his skin temperature runs slightly off, and his movements have an uncanny precision that organic bodies don't usually achieve. His eyes are the same color but something behind them has shifted.
Also known as: Xan