Married to Poseidon by Mistake

Seraphina and her sister Calantha, who are both reborn to the day they choose their husbands ten years ago. In their past life, Seraphina married Prince Ryker and endured brutal betrayal, while Calantha was exiled for marrying a "water monster". Reborn, Calantha snatches Ryker first, and Seraphina resolutely chooses the disguised Sea God Poseidon. After suffering relentless humiliation from her family, Seraphina is finally protected when Poseidon reveals his true identity and unleashes his wrath on the cruel Calantha and Ryker.