A Skithra Queen was part of the resistance against the Sea Devils in another timeline wherein they conquered the Earth. She teamed up with the Thirteenth Doctor and her friends to travel back in time to stop this timeline from existing.
When she set the countdown for the older version of the Skithra ship to blow up, another Queen attempted to stop her. She told the Doctor to leave her behind to fight the other queen and was killed when the ship blew up. (COMIC: Alternating Current)