Erus has royal blood, but his own father treats him like a monster. To the King, Erus is just a savage creature who needs to be controlled. The people also branded him Tyrant. Growing up hated and alone, Erus only wanted one thing, a place where he truly belonged.​To prove himself, he entered a deadly trial where the winner earns a title and a spot serving the King. He was even desperate enough to try making a deal with the God of Death just to win. But then Cana showed up and completely changed his path. Instead of a dark pact with the underworld, an accidental "Master-Slave" contract bound them together. Erus is the Master and Cana is the servant, but their connection is way deeper than a simple spell.​As they fight through the trial, Erus realizes he isn't the only one with terrifying power—Cana’s abilities might actually be stronger than his. They share a bond that goes back to a past someone tried desperately to bury. Now, they have to survive a trial designed to kill them while facing enemies who are just hiding behind their own fear.​In the end, what’s more important: the title that was stripped away, or the memories that were erased to keep the truth hidden?