Captain Hyperion is the character based on the player of the game Honkai Impact 3rd. They can be male or female dependent on the player's actions.
The captain is not referenced in the in-game canon, manga or visual novels.
They only exists in comedic 4-komas and temporary in-game Events, which have been coined "the Captainverse". In it, they play a central part, interacts with other characters and shows emotions as well as a distinct personality.