The Forsaken Moon

Elysia carries noble blood but damaged magic, and the two childhood friends sworn to protect her, Arthur and Leo, turn on her for the sake of a maid named Lillian. The Bonding Tree is severed, her pet's wings are broken, and she is forced out of her warming robe and into a raging storm to die. Rescue comes from Lucas, the mightiest Dragon Prince on the continent, who offers a Sacred Marriage Contract and takes her to his castle. As Elysia's awakening approaches, the brothers uncover a Memory Crystal showing the maid stealing dragon eggs and pushing her into Abyss Lake. Their faith shatters, and their remorse arrives far too late to matter.