The Devil in I

"I heard that Lilith had a guy friend coming, but who are you exactly?" Kaneki inquires from behind the counter. He doesn't look that harmful in his work uniform, but from what I've heard he's next level powerful.
"You know, I'm just a demon lord, no biggie." I chuckle pushing my hair to one side trying to act cool. Arin's monotone voice startles me "My husband isn't a very bright demon lord.". Percy butts in too "What's with this 'Husband' thing?". Then everyone jumps in "Yea I would like to know as well." Annabeth agrees.
Before I can answer Arin begins to explain "I am supposed to marry the demon lord. I don't know why but it's supposedly my destiny."
Out of nowhere Yui grabs onto my arm "But I want to marry Onii-chan!". I take this opportunity to bug Lilith "What about you Lilith there's plenty of me to go around? Hey, Levi you should make Lilith some of your special love potion fried chicken for Lilith."
Lilith's face turns as pink as her hair "errh um" she stutters. "Can we change the subject?" She finally managed to say. "Ok, since you're a 'Demon Lord' aren't you really powerful or something?" Frank quickly questions.
"Earth destroyingly powerful, but like I said earlier no biggie." I smirk. "Ok all mighty Arata." Piper frowns. She continues "if you're the most powerful then you wouldn't mind having a friendly battle with Kaneki and whoever else wants to participate?"
My confidence spoke before I could think "No Problem, but just a friendly competition. No one needs to get seriously injured." Kaneki jumps in "Why did I get volunteered for this?". Annabeth immediately answers "Because we need to gauge how useful he is in combat with a powerful enemy such as yourself so we can formulate strategies if another Titan uprising is in the works."
Everyone takes a minute to let the information seep in before a mysterious man with purple hair squeaks from the corner "I just have to be a part of this.". "Umm just who are you" Percy takes the words from my mouth.
"Most people just call me 'The Gourmet'" he giggles. "Leo, do you think you think you could build a stadium capable of withstanding the battle because I want to join in too." Jason startles Leo from his nap.
"Wha- oh umm yeah I can manage that" Leo groggily responds.

Notes

If anyone wants to guess what anime my profile picture is from and get it right I'll update any story of their choice and give them a shoutout