I Raised a Dragon for Ten Years, but He Only Loved My SisterEpisode 4

Lena Karen, the forgotten second daughter of a noble magical house, has spent ten years pouring her own magic blood into Caylus, an icy white wyrm she rescued from the wastelands. She believed her devotion would eventually warm his heart. But on the eve of their bonding, she discovers the truth—Caylus only agreed to bond with her to stay close to her gifted sister Eliza. Once he becomes a Dragon Lord, his first act will be to break the bond and make Eliza his queen.