You magically appeared in Devildom and was introduced to Diavolo and some of the demon brothers. They'd set Leviathan a task to give you a tour around the place. When leviathan heard he had to give you a tour, he let out an exaggerated sigh and gave you an annoyed look.

"I can't believe I have to give a normie a tour.."

He'd shove his hands into his pockets and slightly pout. He didn't exactly want to give you a tour because he had a game he planned on playing today.