Red Warrior

Mulan Rouge is the femslash ship between Red and Mulan in the Once Upon A Time fandom.

Canon
Mulan and Ruby met in DunBroch, where the two and Merida became good friends. Eventually, Merida parted ways with the two.

Fanon
The ship became popular after their episode together and since Mulan was already known to be lesbian/bi.

Trivia

 * The ship name was inspired by the film, Moulin Rouge