Obey me

Not everyone who shares your goals is your ally

Mammon: "Asmodeus...! You rotten bastard...!"

Asmodeus: "AAAAAH! I can't take this anymore! I wish you'd just disappear! You can go burn in the fires of hell for all I care! If I could snap my fingers and send you there right now, I'd do it!" 

Mammon: "That's it! You shut that big fat mouth of yours RIGHT NOW, you *************************!" 

Y/n is eating popcorn while watching. 

Asmodeus: "Oh yeah? Well, you're money-grubbing trash! A scumbag who'd sell his soul for a Grimm!"

Y/n: "I'd give him 5 Grimm for it." 

Satan gives her a look. 

Asmodeus: "The only thing that might make up for your awful existence is if you ended it! Now!" 

Y/n looks at Satan for help. 

Satan: "All right you two, that's enough. Stop throwing pillows at each other. You're sending dust flying everywhere." 

Levi: "It's no use. They won't listen. It's like they don't even hear us." 

Beel: "The food here at the Demon Lord's Castle sure is something, huh? The shadow swine offal they served at dinner was amazing." 

Mammon: extensive cursing. Asmo is complaining about Mammon. 

Mammon: "WHAT?! SAY THAT AGAIN! I DARE YA!" 

Levi: "How long are they going to keep going at each other like this? It's a total waste of time. They're getting nowhere, and it's driving me crazy." 

Beelzebub: "Mmm, I can't wait for breakfast tomorrow..." 

Satan: "What brought about this, anyway?" 

Y/n: "Funny story."

~Flashback~

Lucifer: "All right, I'm going to call this officer's meeting to order. To start things off, Lord Diavolo has an announcement for us." 

Diavolo: "Yes. Well then, I assume that some of you have already heard the rumors about the group retreat. And they are true. I'm planning an exchange party between demons, angels, and humans to be held at my castle. I have a feeling that this will be quite an interesting experience for all of us." 

Lucifer: "Maybe for you, but for me it's simply going to mean more headaches." 

Diavolo: "Now, now, don't say that, Lucifer."

Satan: "A group retreat, huh? I'd heard a number of rumors, but I never thought they were true." 

Asmo: "So, demons, angels, and humans will all get together and have an exchange event? Nothing like that has ever happened before, has it?" 

Diavolo: "No, indeed not. But there has to be a first time for everything. And you all are going to be present to witness this particular first." 

Mammon: "A group retreat? Just the fact that you'd call me it tells me it's gonna be a huge hassle..." 

Beel: "Will there be food? ...Good food?" 

Diavolo: "Ah yes, why don't I let Lucifer give you a rundown on what we have planned." 

Lucifer: "The exchange party will be held at the Demon Lord's Castle. In addition to spending the night there, you'll be attending several events, including a dinner party and a formal dance." 

Beel: "A dinner party..." 

Diavolo: "I assume you must have some questions?" 

Y/n: "What's that?" 

Diavolo: "It's my castle, the place where I live, as the name implies." 

Satan: "It's hands down the most magnificent, impressive structure in all of the Devildom." 

Leviathan: "And it's like the castle where the heroine lived in Fantasium Fantasia 9! Now,  when it comes to the Fantasium Fantasia series as a whole, it goes without saying the fourth installment is a timeless masterpiece. Afterward, the games went 3D polygonal and BGM composer both left, so the general opinion..." 

Y/n ignores Levi and focuses on Lucifer. She tunes back in halfway through Asmos' speech. 

Asmo: "...it's like something straight out of a fairy tale. It's beautiful."

~With Belphegor~

Belphegor: "They're having an exchange party...? Hmph, ridiculous. But did you say you managed to make a pact with Beel? Because that's a far more important development to me! You didn't strike me as the type of person who would come through for me, so I didn't really have my hopes up, honestly...But you seem to have actually gained their trust, as surprising as that is. You've managed to make pacts with Mammon, Leviathan, and Beelzebub now...Finally, you're halfway to your goal. Now..." 

Y/n isn't paying attention anymore. 

Belphegor: "Pay attention!"

Y/n: "Ah!"

Belphegor: "Now, let's hear what else you have to report. What did Lucifer say about the room up here in the attic?"

Y/n tells Belphegor about Lucifer. 

Belphegor: "Hmm...so let me see if I've got this straight. There's a spell on the staircase leading up here that ensures that no demon aside from Lucifer is able to climb it. However, it turns out that humans and angels can climb it since they're not demons. And what's more, Lucifer seems confident that you haven't found out about this room. Since this is Lucifer we're talking about, I assumed he would've put some sort of spell on this room as well, like he did with the staircase... So then, what's going on here? How is it that you are able to see this room? Well, I guess it doesn't matter. Either way, it's good news for us. Because this means that Lucifer doesn't think you've been in contact with me. Also, I've learned something new here. Namely, that you're not just any ordinary exchange student-" 

Y/n: "I'm ten." 

Belphegor: "Besides that. I suspected as much. There's a reason you were chosen to come here." 

Y/n: "Diavolo wanted a child." 

Belphegor: "Really?" 

Y/n: "Yeah." 

Belphegor: "Well then, your next step is clear. You can worry about making pacts with the other brother later. Right now we've got bigger fish to fry. You'll be going to the Demon Lord's Castle for this exchange party or retreat or whatever it is, right? You need to search for clues as to what exactly it is that makes you so special while you're at Diavolo's Castle. I'm sure you're curious to know why it's you were chosen. I can't help."

Y/n: "Belphegor."

Belphegor: "What?"

Y/n: "I lied."

Belphegor: "What?"

Y/n: "About why I'm doing this. I'm doing this..."