Honestly? I'm not at all surprised at the fact that Minos moved into the Colossus. I mean, he used to come here two to three times a day to check on Nina, just to make sure she was doing all right without her knowing. He even frightened me quite a few times when I was passing by.
I actually didn't mind his secret visits, as he always helped us tidy up the Colossus while he was here because he felt sorry for "disturbing us." I once followed him, trying to learn how he tidied up a room, but my eyes couldn't even keep up with his movements. Probably only someone as fully committed to one thing as he could achieve such mastery.
Then, one day, Nina finally discovered Minos following her, so she yelled at him and said, "If you like coming here so much, why don't you just move in!?" It was almost as if Minos had been waiting for her to say that. He moved in the very next day.
Of course Nina wasn't happy about it, but I'm sure my work will be way easier now that Minos is here!
—Vice

It's alright. I don't mind you staring at that broken horn on my head. It'd be unsettling for anyone to suddenly have someone with such an unseemly appearance like me around. Oh, no need to be sorry. It's only natural to be curious... or scared. Even my own family couldn't hide their disgust at how I looked. I don't mind telling people about the broken horn because, to me, it was the day that I was reborn.
Back then, Mr. Andersen was not my master, but my target—to become the head of the Andersen family. The Andersens' former butler was also not yet my mentor at the time. I charged at Mr. Andersen with my sword drawn, but didn't manage to even touch his clothing. That was when I lost my horn; the former butler stopped me in my tracks and snapped it in half. I was pinned to the ground, waiting to reap the consequences of my defeat. It was obvious to everyone there that I was an assassin, but Mr. Andersen told them all that I was his butler's "undisciplined apprentice." Instead of giving me the punishment I deserved, he took me in, and from that day on, I said goodbye to my broken horn and despicable past.

I didn't realize that you'd be so interested in my past, %s. If you really want to know, okay, I'll tell you.
I, a demi-human, was born in the slums. My brother sold me to a brotherhood of assassins so there was money to feed my family. As the hand of fate had willed it, I came to the organization from a home that loved me not, and then took on a job from the organization and came to the Andersens.
My mission failed, but the head of the Andersens took me in. When my master asked me if I wanted to stay, I accepted the offer without hesitation. With them, I was treated like an individual for the very first time. It was also the first time that I learned that even someone like me could be cherished and respected as a person.
That was when I finally I'd escaped from the hands of fate. I'd found a place where I belonged. Only my unwavering loyalty to the Andersen family suffices to return the kindness they gave me.

So you do remember the fallout that transpired between Miss Nina and me. No need to be concerned. The misunderstanding has been cleared up. That said, I will never forget the incident that led to this grave misunderstanding.
Back in the days when I was still with the brotherhood of assassins, I was used to the smell of blood and had grown numb to its stench. One rainy night, after I disposed of an assassin who took an attempt on Mr. Andersen's life, I was in such a hurry to confirm my master's safety that I forgot I was covered in blood. It was all over my collar, my hair, even my face. And I ran into Miss Nina like that. She was so shocked that she ran away, screaming and trembling in fear. I called out after her in confusion, but she didn't turn back. When lightning streaked across the sky outside the window, I saw the horror show that I was in the reflection of the window.
Then, she became distant and even tried to avoid me. But what I resented more was that my negligence revealed my ugly side to her. It was a mistake that I would never repeat again.

You think I'm a "perfect" butler? I'm honored to receive such a compliment, but there is always room for improvement in my line of work. Serving my master, receiving guests, fishing for intel, stopping assassinations... these are all basic requirements for the job. Although my work as a butler sometimes does overlap with what I used to do as an assassin, the purpose that drives me is very different now. Everything I do now, I do for the Andersen family.
Once, my mentor and I assisted Mr. Andersen in quelling a conflict within the family and safeguarded the Andersens' assets. Now that my mentor is no longer with us and I've succeeded him, I've gained the right to be vocal within the family. Thus, my responsibilities now include teaching Miss Nina on top of assisting my master. I understand Nina's desire to be independent and self-reliant. Still, as the family's butler, I have to put her safety first, as she is the future head of the Andersen family.
What was that? "Even at the cost of being despised by Nina?" No. How would that be all right for me? Even so... I have made up my mind. I will not budge until I feel that Miss Nina is ready to be independent.