CREWMATES: Identify the imposter, eliminate them, and complete tasks in spaceship.

IMPOSTER: Covertly sabotage the mission either by killing the Crewmates before they complete all their tasks or trigger a disaster that can't be solved.

Of course, you were one of the innocent crewmates. And He Xuan, one you considered friend is an imposter.

One by one your comrades were killed until there was only the two of you in the ship. However he did not kill you, he instead kept you with him.