My mission pt 2 (Diavolo x assassin reader)

Y/N's POV

It's been a few weeks since my release, and they were going pretty good. I was able to make amends with the demon brothers, as well as the angels and Solomon. I nearly cried when Lucifer forgave me a lot quicker than I thought he would.

Considering the circumstances, I expected him to threaten me or something. But I guess even he has a soft side. I've also regained my strength and stamina. I had been training almost every day, preparing myself for the upcoming trip to the human world. My motivation was to save my sister, so I really pushed myself during training.

It was the night before our trip, and I was feeling anxious. I had heard stories of people who dared to go against my boss's wishes, and they didn't live to tell their tale. Which made me even more concerned for my beloved sister.

My mind was filled with so many terrible thoughts, so I ended up falling into an uneasy sleep, not knowing what kind of illusion my mind was going to show me later that night. A nightmare filled with blood and tears.

3rd POV

Diavolo was having a hard time getting to sleep. He wasn't nervous about dealing with Y/N's boss, he was worried about Y/N herself. She seemed terrified any time they had spoken about him these past few weeks. He could only imagine what kinds of things he had put Y/N through over the years.

As the demon prince wandered aimlessly, he ended up in front of Y/N's bedroom door. He thought it was silly of him to worry so much, but then he heard whimpering from inside the room. Worry consumed him as he quickly opened the door. The human was tossing and turning, and murmuring incoherent words.

Diavolo hurried over to her, and gently shook her small form. He could see tears falling from her cheeks, and it reminded him of when he had released her. Y/N's eyes suddenly opened, and she sat up in a panic. She looked around as she panted for air, and her eyes landed on the prince.

"Are you alri-?" Y/N reached for him and hugged him. He could feel her small body trembling. He had noticed that she had reverted back to way she was acting before she tried to kill him. Back to the sweet, sensitive girl he had gotten to know.

He was quite happy to see that her "fake" personality wasn't fake at all. It was her true self. The one hidden beneath all the blood and chaos. Not the personality her boss had created and thrust upon her by force.

"T-There was blood....and the boss...and-!" Y/N tried her best to explain the nightmare, but she was trembling so much, and it made it harder to speak. "Shh. It's alright. I won't let him lay a finger on you, or your sister tomorrow." Diavolo started to stroke her hair softly, which seemed to calm her down a little bit. She sniffled as she clung into his body, as if letting him go would make him dissapear.

"I-I.....can't lose you." Diavolo's eyes widened. Those words stirred something within him. He knew he probably wouldn't have much trouble handing a mere human, and he had a feeling that Y/N knew that too. Yet she said that anyway. "Don't worry. I'm not going anywhere." He whispered softly. Again, he knew this was the work of her boss.

"P-Please...don't...leave..." Y/N's voice was so soft, so Diavolo looked down. The human had nodded off in his arms, and he sighed softly, but then chuckled. "What am I going to do with you?" He was about to lay her down, but she somehow had a tight grip on his shirt. He thought about his options, but really only had one.

He carefully laid down with the ex-assassin in his arms. He managed to pull the blankets over the two of them, and fell asleep. Y/N didn't have any more bad dreams for the rest of the night.

Y/N's POV

"Are you ready?" Diavolo turned to me and asked. A glowing portal was on the wall, and I nodded slowly. When I glanced at Diavolo, he gave me his classic smile. My heart skipped a beat as I faced the portal again.

When I had woken up this morning, Diavolo was in my bed with me, holding me tightly as he slept. I remembered what had happened the night before, and how I asked him to stay with me. I was kind of embarrased when he woke up, so I did my best to play it off. "Let's go." Diavolo held out his hand to me, and I took ahold of it.

When we exited the portal, we were somewhere all too familiar to me. Everything looked normal, but I knew that this town was a lot more than it seemed. I felt Diavolo squeeze my hand, and I took a deep breath before I started walking. My heart started racing a little, but I focused on the warmth from Diavolo's hand to compose myself.

"See that brick building over there? That's it." I whispered softly, and Diavolo nodded. As we got closer to the building, a few men started walking towards us. I squeezed Diavolo's hand, and he let go. "Heeey! What's up, Y/N? It's been a while." One of the men came up, and leaned down. His name was Devin. He was basically my boss's right hand man.

I could smell the smoke from his breath, and it almost made me gag. "Where's the boss?" He scoffed as he looked towards the brick building. "In his office. But hey, who's the dude? He a friend of yours?" Devin looked to Diavolo, and studied him for a few short moments. "It's none of your business who he is. Now if you'll excuse me, I need to report to the-"

"Hey man. Isn't he the ruler of Devildom or whatever? He looks like the picture the boss showed us. Word is, our little assassin was supposed to kill 'im." One of Devin's flunkies spoke. I mentally cursed as I moved closer to the demon prince. "Indeed I am. If you don't want any trouble, I suggest that you move aside." Diavolo smiled at them as he glanced at me. "Go on. I'll be fine. I promise to simply knock them out. " I nodded as him as I made a break for the brick building. I'm glad he wasn't killing them. I've seen enough bloodshed for a lifetime.

My hand hovered over the doorknob, and I slowly opened the door. The first thing I saw was S/N, who looked relieved, but terrified at the same time. The next thing I noticed was that my boss was holding a knife to her neck, and had a wicked grin on his face.

"Y/N! It's been a while, hasn't it?" "W-What are you doing to her?!" The man sighed as he pressed the back of the knife a little harder on S/N's neck. "Some of my men told me you had entered the city earlier, but the odd thing was you apparently appeares out of thin air." My boss started explaining. I kept my eyes on my sister as he spoke. Tears were starting to form in her eyes. Her completion was a little pale, so I knew she was still pretty sick.

"The only possible way you could've done something like that is because a demon helped you. And a demon wouldn't help you if you murdered their ruler, which means that you failed the mission." I tensed up for a second, but then I spoke as calmly as I could. "I did kill him. Not all demons were okay with the exchange program, so I got one to help me. Besides, he was such a pushover." I felt a little bad for smack talking Diavolo, but I'm sure he would understand why I said that.

"A pushover? Well, I guess I can forgive you. You are trying to save your sister after all." I turned around after hearing a familiar voice speak up. Diavolo was standing there, but he looked much different. He had large horns on the sides of his head, and giant black wings were sprouting from his back.  This was his demon form.

"Heh...you're the prince of demons. I guess my little assassin lied to me." My boss didn't even break a sweat at Diavolo. He kept the knife right where it was. "Hahaha! That's right. Now, would you kindly hand that young lady over to us?" Diavolo had his normal smile on, but I could he was being serious. "And if I don't?" My sister let out a little yelp as my boss squeezed her tighter.

"Wrong choice, buddy!" My eyes widened as I turned around again. All of the demon brothers rushed into the room, and managed to get S/N away from my boss. I could barely see them moving. "Y/N!" My older sister was now in my arms, and she was crying. "It's alright. We're going to get you cured, okay?" I started crying too. All of our struggles and pain had just been demolished.

"Damn you! You were supposed to kill Diavolo!" The man that used to be my boss yelled out. I glared at him as I helped my sister stand up. "Well, I actually tried and got caught because I hesitated. I just couldn't do it. But I was given a second chance." I smiled up at Diavolo, who wrapped a protective arm around my shoulders.

After that happened, Diavolo decided to let the man go, but he would pay for the last treatment that S/N needed. He begrudgingly agreed, and after a couple weeks she was completely healed. Since we didn't really have a home to go to, Diavolo offered to let us stay in Devildom. Of course, S/N was a little concerned, but I reassured her that we would be safe there.

So we took what little belongings we had, and moved to Devildom. My sister was going to live in Purgatory hall with Solomon, Luke, and Simeon. And Diavolo insisted that I stayed in my room in the castle, which is what I did.

Not long after that, Diavolo asked me to be his girlfriend. I was shocked, since I had never been someone's girlfriend. But I accepted. He had shown me compassion like no one else has before. And he agreed to take things slow since I wasn't used to romantic things yet.

"I can't thank you enough, Diavolo. You've done so much for me and my sister..." It was late, and I had gone to Diavolo's room to talk to him. "It was no problem. You deserved a much better childhood than the one that you got." He grabbed my hand softly, and I could feel my face getting warmer.

"I-Is there anything I can do for you though? I still feel like I need to give you something in return." Diavolo smiled as he slowly leaned down, and pressed his lips against mine. My mind went blank. I wasn't sure what to do since I had never been kissed before.

"All I need is you by my side. Can you do that for me?" I nodded silently as he kissed me again. This time I leaned in a little bit, and enjoyed the moment of pure bliss.