Voltron Force (2011)

S1E52 The Sleepers Awaken

Adam and Teela explore a long-forgotten castle that once belonged to a sinister Lord and Lady who practiced dark sorcery by draining life from the surrounding trees, causing them to wither and fall into a deep slumber within their coffins for centuries. While soaring on winged horses, the slumbering Lady Valtera and Lord Tyran stir from their sleep. Disfigured by his malevolence, Tyran is unrecognizable to Valtera. Mistaking Adam for a potential partner, Valtera seizes him as her servant, prompting Tyran to unleash chaos in a desperate bid for power, ultimately capturing Teela as well.