Son Of Poseidon, King Of The Gods ((ON HOLD))

Vili, god of will/determination, Ve, god of spirit, and Vitharr, god of vengeance, all from Norse mythology, are plotting a Ragnorak that will allow them to take over the world and, eventually, the universe. Loki found out about it and was about to warn someone, but Ve took him over. That was approximately a thousand years ago.
By the time the Avengers and the Olympian gods found out about it, the plan was in its final stages of planning and preparing, giving them only about two months to gather an army of skilled warriors willing to fight for our world.
They started by going to the UK and recruit some of the Hogwarts graduates, and find out about the soul society in the process. Deciding that, while they were at it, they should recruit some of the soul reapers from the soul society. Some of them venture into one of Nico's domains, while Percy and Orion go to Asgard to ask Odin to aid in the war. But, what they find isn't what they expected.
Odin is Loki, and Loki is being possessed.