Koei Tecmo has just uploaded an action gameplay trailer of Cordelia in Fire Emblem Warriors, which you can watch just right above.
The beautiful Pegasus Knight from Fire Emblem Awakening is the first one to have a gameplay trailer released from the Japanese side first. As you can see in the video, Cordelia, along with other mounted class characters, will be always mounted on their rides even when attacking. Also, some maps in Fire Emblem Warriors will have routes that are only traversable by flying classes like Pegasus Knight.
Fire Emblem Warriors will be released for Nintendo Switch and New Nintendo 3DS in Japan on September 28 and in the West later this Fall. You can read more recent information about the game here.