The Sea's Rebellion

What if Poseidon didn't marry Amphtrite to claim inheritance to the sea? What if he married her because he was looking for a mother for his child but made a mistake. Lunelle, Poseidon's lover and mother of his child, had a secret ability. She could see into the future. However she could only use this once every century. Using her ability she foresaw the death of Poseidon and the loss of many of her family. Using her knowledge and the trust her lover gave. Lunelle drugged the sea god, heavily with a sleeping powder. Therefore taking his place. Leaving him nothing but his child who looked exactly like a miniature of him. Centuries later, Brunhilde, in order to stop the gods from destroying mankind declared Ragnarok again. The gods agreed but unknown to them, the eldest valkyrie has an ulterior motive. This time it involves a mortal gang leader.