Betrayed by the Alpha, Betrothed to the Dragon King

Seraphina is a Sunfire Elf Princess whose fiancé, Alaric, took her adopted sister, Vesper, for his savior, only to treat Seraphina as Vesper's sacrifice. She then schemes a marriage swap to marry the powerful Dragon King, Darius. When Alaric realizes Seraphina was his true savior, he's full of regret. But Seraphina's already become the realm's supreme Dragon Queen.