Cassius is a born Saint of the Waving, beloved by all the Wavings. Every Remnant obeys his commands, yet his mother Leviathan abandoned him in the human world to fend for himself.
In the first half of his life, he fought for humanity, taking the lives of Remnants beneath a shower of people's cheers, hailed as a hero. But his mind was filled with the Remnants' anguished cries. He was conflicted and lost. If humanity's glory was built on the suffering of the Remnants and the Wavings, was humanity guilty? In his pain and confusion, Cassius could never find the right path.
Then the Black Tide arrived. His childhood friend, who had been crowned a saint, disappeared, and he was branded a heretic and sent to the tribunal. Because he had not been affected by the Black Tide, people suspected he was a Resonant of the Waving. It was an implausible accusation, yet people consumed by fear believed it.
But he did not die. The one Remnant he had spared saved him, and he met Floro and learned of her dream. Taking it as his guide, he turned the Wandering Paradise into a true world, granting the Remnants real life and wisdom, and severing the fate of the Wavings from civilization.
When they met again, he stood beside Leviathan, facing his childhood friend in battle. He would defy the entire world, both humanity and the Wavings.
