The Sovereign's Sigils

In an alternate future where ninety percent of the earth's surface has been submerged in water. The rule of law is enforced by a man named the Leviathan. He has achieved partial dominance of the world by the might of his numerous Marines. Among them are his Cryptids; supernatural entities with the ability to draw power from sigils scattered across the surface of the earth. They are is fortification against rebels and his sword against the creatures that stumble from the ever shrieking red mist called the Mirror. It is a time of danger and destruction, where creatures that actively wish to purge humanity roam the seas and the remaining piece of land forge against their existence. Humanity is at its brink and a group of teenagers have decided to shoulder the responsibility of saving it.