Mulan is a recurring character in Once Upon a Time. She is the roleplay character of SilverFlight
Before the Dark Curse was cast, Mulan serves in the army of the Emperor of her native land, and she proves herself in battle.
Later Mulan encounters Belle outside the den of the Yaoguai in her home Empire. Belle lures the creature out of its lair, but it attacks and Belle runs from it. Mulan then fires an arrow at the beast, making it run away. She then goes to Belle, but berates her for scaring the beast and ruining her chance of killing the Yaoguai and saving her village. She storms off into the woods, telling Belle that the best way she can help is to stay out of her way. When Belle is later accosted in Mulan's village by her former traveling companions, Mulan attacks and drives them away, saving Belle in the process, but receiving a wound to her leg.
When Belle inquires as to why Mulan saved her, Mulan tells her that Belle was able to find the Yaoguai and track it in a matter of hours, while it had taken her months to do so. She asks Belle to help her track the beast, and then Mulan will kill it. Belle agrees. As they go after the Yaoguai, Mulan discovers that her injury to her leg is worse than she thought, and tells Belle that it is up to her to go and defeat the Yaoguai. Belle at first refuses, but after Mulan encourages her takes the sword and goes after the Yaoguai. After turning the Yaoguai back into Prince Phillip (played by Julian Morris), Belle goes to Mulan and introduces the two of them. Belle decides to go back to Rumplestiltskin and leaves the two of them behind and thus starting their friendship.
Later at some point, Mulan joined Prince Phillip on his journey to find Princess Aurora They were on the journey when The Evil Queen cast the Dark Curse, however the area that they were in was spared by the curse merely freezing them in time for 28 years. When Emma Swan broke the Dark Curse in Storybrooke, they continued their journey.