Sealed With A Kiss (Guardian Demon!Levi x Reader)

                                    

                                          
While you closed your eyes with a focused aura, the dimly lit room, the smell of smoke and candles lighting up the circle, were slowly deteriorating as you spoke. The smoke began to circle around the area you made, and slowly, it grew in height. The wind that was generated was causing havoc to your room, blowing papers everywhere as you continued your chant. 
Once you spoke those last words, you opened your eyes to see the smoke has created a large dome, glowing a bright blue color. "It worked" you breathed out. The tip of your finger touched the dome, and in an instant, you covered yourself as a large mass of wind blew you backward.
Dusting yourself off, your breath hitched at the sight before you. There stood a man adorning a large black kimono with an interesting wave-like design on it. Upon looking up to his eyes, you held in your breath as you saw them. His collarbone had blue shards scattering along his skin, his cheekbones were decorated with blue marks, and upon his head were blue horns.
"No no no" you ran to your book, flipping through it frantically. "You weren't supposed to look- look like that!" you shouted in fright.
The demon looked at you with an annoyed expression, scoffing at your words. "Who did you expect you mortal?"
"Something other than you! You're all dark for goodness sakes!" you said, clutching your book in disappointment. 
"Tch, I guess you failed to summon your 'guardian angel' huh? You little shit" he chastised.
Flipping through the pages, you knew you did everything right, so where the hell did you go wrong? While you searched for your answer, the demon had approached you, cornering you. His eyes glowed brightly in the dimly lit room, making your knees weak and your saliva caught in your throat. "Y-you're not here to k-kill me, are you?" you mumbled.
"I'd love to, but because your stupid, careless self summoned me, I have no choice but to not" he glared at you. "Now, instead of a guardian angel to protect you, you've summoned the demon kind instead. We use methods far worse than the likes of your kind, and if you feel guilt for whatever I do to protect you, if that's what you wish, you're on your own."
You were left speechless. Placing a hand to your head, you brushed through your hair in disbelief before your frantic eyes looked at his. "Can I not sign a deal with you? I don't have to do I?" 
He raised a brow, rolled his eyes, and scoffed. "To summon me was a hassle itself, but to decline the deal you've already set will cost you more than your life," he said. "It'll cost you your soul to slave away for eternity at my mercy."
Gulping, you were left with no choice but to oblige. "Fine! I don't have any other choice."
"Great, now to seal the deal, I'll have to do what I would never want to ever do" he grimaced.
"Right, how do we do the contract?" you asked, but you could tell how repulsed he is by the idea of it. You have yet to get an answer until he walked closer to you and suddenly cupped your face, leaning in. Your hands held his shoulder, pushing him away. "What do you think you're doing?!"
"What does it look like I'm fucking doing? Sealing the deal" he leaned in closer, but you retaliated. 
"No wait, that's not how you do it! Shouldn't there be a paper or something for me to read and sign?" Nervously, you tried to hold him back, but he remained as close as he was.
Sighing, he replied, "I don't make the damn rules. To seal these deals with the likes of me, we must do it with a kiss. Why? I have no fucking clue, but if you want to change that rule, be my guest. Don't call for my help when you're burning alive before you even get to stage one."