She looked up from the piece she was toying with and into his eyes, "But I was worried. Once I knew who you truly were, I was afraid I wouldn't be strong enough to turn you. Your potential as 'The Artificer' easily puts you on the level of something with a Longinus-Class Sacred Gear, by itself. Add in your Sword Birth and its Balance Breaker..."
She trailed off and shook her head, "I'm proud of my strength. I'm strong, for my age. Yet, I knew I wasn't strong enough to turn you even with all eight of my Pawn pieces." She gently stroked the mutated Pawn, "So I did something I'd sworn I would never do." She smiled softly, "I asked my brother for help in this matter. I abused my connection with him to get my hands on this single piece. I don't know what it cost him, but I know it wouldn't have been a small price. He wouldn't ever complain about it and would do almost anything he could for me. I took advantage of that just so I could have you join my Peerage."
She set the piece in between them and moved the box containing the remaining ones aside. He'd remained silent as it was clear she wanted to get all of this off of her chest. She gently tapped the top of the piece with her finger, "I did all of this because you are my one hope for a bright future."
Her eyes bored into his and he could see how serious she was being, "I am engaged. His name is Riser Phenex, third son of the Phenex clan. And I HATE him. But even more than that, I can't stand being in a position that means being forced to marry someone like him. I want my freedom. I want to choose who to love, who I marry, and every other aspect of my life. You are the key to that."
She picked the piece up and held it tightly in her fist, "If its alright with you, I would very much like to do this right now."
Junichiro nodded in understanding. Despite the contract being signed, it wouldn't be 'real' until he'd become a devil. He climbed to his feet and moved to sit next to Rias on the love-seat, "It's fine. Let's do this."
Rias smile gratefully and placed the chess piece against his chest. Her demonic power flared causing the piece to glow and a large red magic circle to appear behind him, "Thank you for joining me, Junichiro"
The chess piece glowed brightly and slowly sank into his chest. In just a few moments, it was all over. Junichiro looked at his chest, not feeling anything different, and even flexed his one good arm with a small frown, "I don't feel any different."
Rias giggled lightly, "It's not an instant process. If you were dead it would instantly revive you, but the full transformation into a devil takes between twelve and twenty-four hours."
Junichiro pouted at that a bit, but quickly changed his mind. He hopped to his feet and smiled brightly, "I wonder..."
Without another word, he left the room and made his way to his workshop. He immediately headed to his wand display and began using them to scan his body and catalog the changes happening. He ignored Rias following him, too engaged in tracking the changes happening to his body.
It was easy enough for him to find the Pawn piece, it was attached to his soul in a similar manner to how his Sacred Gear was. There was a difference though. Unlike Sword Birth, the Pawn piece was making small changes to his soul. Nothing drastic, but he could see the minor tweaks it was making that would turn his soul from human to devil.
As he continued to scan, he was shocked to see what the changes to his soul were causing. The soul was the central most part of a being. From within his soul, the changes radiated out and slowly began changing his flesh to match his soul. As he watched the process through the information being transmitted to him, he wasn't sure if it was something he could emulate, just yet.
It was a very complex and delicate process and his scans told him that the special material the Pawn piece was made of played a huge role in not causing damage due to the changes. It also seemed to help drastically with the piece fusing to the soul without causing damage from the process. It was remarkably similar to watching the Sacred Gear fuse to his soul, but also rather different. He wondered if the Sacred Gears used the same, or a similar, material in their construction.
Rias silently observed Junichiro for some time before her curiosity got the better of her and she asked, "What are you doing?"
Junichiro jumped slightly before turning to face Rias, "Sorry, I didn't even realize you were still here." He cleared his throat to get over his embarrassment of getting so deep into his curiosity that he'd forgotten all about his new boss, "Well, I wanted to know what was happening to me to actually make me into a devil. To understand that I am using various diagnostic spells through these wands to get readings and try to comprehend it. I may not be anywhere near as smart as Ajuka Beezlebub, but I am pretty intelligent. With the help of my tools I can have some understanding of the process."
He set the wand he was currently using down and picked up one meant specifically for detailed scans of the soul, "For example, did you know the process of turning me into a devil is similar to the process of binding a Sacred Gear to a human who didn't have one previously?"
Rias blinked at that, "Truly?"
Junichiro nodded, "Yup. I'm getting similar readings to when I bound Sword Birth to myself."
"Wait you weren't born with Sword Birth?"