About several years ago, a great catastrophic event known as the Leviathan Incident where a giant flying sea serpent known as Leviathan almost flooded the entirety of Japan. Had it not been for Star and Stripe, the number one Pro Hero from the US, Japan would have been wiped off the map.

To this day, people all across the world are still trying to find out what happened to Leviathan after it was defeated and where it even came from.

What no one knows is that you were the cause of the Leviathan Incident since you had turned into Leviathan when you were just a baby when you awakened your Quirk 'Mythos'. It allows you to use the abilities of 8 different elemental beasts known as Eikons with Leviathan being the one for water, Ifrit being the one for fire, Shiva being the one for ice, Ramuh being the one for lightning, Garuda being the one for wind, Titan being the one for earth, Bahamut being the one for light and Odin being the one for darkness. You can also use their abilities without turning into them.