Kisuke explained everything he could to Soifon pertaining to what they just watched, however, he knew that she wouldn't fully understand it without experiencing it herself and that's a long process if they were not going to that side.
'Anyone can do flashy things, but only a few could be truly horrifying. How will I be able to explain doubling power every ten seconds limitlessly or dividing power to the point of nonexistence?' Kisuke thought to himself while cleaning up, "I think that's enough for now. Let's have you fulfill your side of the deal."
Soifon froze. Now that it has come to this, she started becoming nervous, 'It was really stupid of me to not ask about this experiment before agreeing. But I have a feeling that I would lose my footing in the negotiations if I were to ask for specific details.'
Breathing deeply a few times, she finally said, "I agreed to the experiment thinking that you wouldn't put my life in danger, but am I wrong?"
"I won't deny that there are any risks, but I already arranged everything so that even in the event of a catastrophic failure, your life would be safe and you can still go back to the 2nd Division without any problems."
Soifon sighed in relief, "Alright. I'll trust you. But what are you going to do exactly?"
"For now, follow me."
.
.
.
Kisuke and Soifon left the mansion and went underground to reach a detached building that was at least 5 times larger than the mansion, "What's with you and underground bases?", asked the latter.
"It's convenient so why not?"
Kisuke led Soifon to a large room of the detached building that only contained a few things and the most prominent of it all was the large glass tube filled with a blue solution and in the middle of it, "...A fetus?" Soifon asked.
Kisuke then suddenly turned to Soifon and said, "The experiment is transferring your soul into a physical body and seeing if you could use your Shinigami powers while in it."
"...Are you serious?"
"I've been at it most of the years I've been on the other side. I'm pretty serious about it."
"...And what for?"
"It started as a curiosity, then a genuine interest. I wanted to know how Yoruichi and I were capable of using our powers despite having a physical body. And as an extension to that, how are the Humans on that side different from the ones here."
"Then what happens if this is a success?"
"With sufficient mastery, you'll be able to use Magic and Ki too."
"You know that's not what I'm referring to. What do you want to happen creating something like this?"
"..." Kisuke went silent for a moment before saying, "This is not part of our agreement."
Soifon gritted her teeth, "Do you really think that I'm stupid enough not to believe that this pertains to the fate of the Soul Society!?"
But instead of answering her question, Kisuke asked, "Have you noticed anything out of place with the videos I showed you?"
Soifon was startled and thought that Kisuke was escaping from the topic, "This isn't about that!"
"It isn't? Well, anything show in that is out of place for you, but if you can't notice it, you're still not ready to hear it."
"...What do you mean?"
Kisuke turned around and started operating the panels, "Once you start asking about it, you'll have an idea of what I'm anticipating. However, until that time, I'll keep my mouth shut."
"Is it really that hard to tell me?"
"Yes. As you are now, you'll see me as the most evil man in the world."
Soifon clenched her fist hard and asked another question, "Does Yoruichi-sama know about this?"
"I didn't tell her anything about it, but if it's her, she knows what I wanted to happen. In the first place, I don't know if what I'm thinking is really going to happen. Let's just say that I'm preparing for the worst and this is one of my insurances."
"And she allowed you to return to become that evil man?"
"I have her full support."
"...Then what do you really want?"
"I already answered that."
"No. I'm asking you what's making you do all of this?"
Kisuke's hands stopped and he slowly turned to Soifon only to see her staring at him seriously. Kisuke smiled gently and said, "You may not believe it, but this is to protect all those important to me."
Soifon stared at him for a few more moments before sighing, "What should I do?"
"Just like a Gigai, you'll be entering that fetus."
"...I'm not going in that and waiting for years to reach full maturity, will I?"
"No. It's a fetus I created from very special ingredients. It's special that its DNA is not set and only when a Spiritual Body enters it will start developing. And once it starts developing, it'll only take a day or two for it to get the same shape as the Spiritual Body that entered it."
Soifon approached the glass tube and asked, "And the caveats?"
"According to my calculations, you'll only be able to stay in this... Let's call it Gigai for now. You'll only be able to stay within this Gigai for 30 days before the fuse becomes permanent and it'll become your flesh and blood regardless of the complications. With that in mind, you'll enter it and after two days, we'll do various tests for the next five days. After that, I'll separate you from the Gigai and you'll enter another one to resume the tests."
"You'll have to separate me? I can't do it on my own?"
"Yes. While it sounds simple, the process of entering and exiting it is a lot more complicated under the hood and any oversight from me could cause you harm. Both of us don't want that."
"How many times do I have to repeat this experiment?"
"If it's up to me, I want to do this at least a thousand times, but that's clearly unrealistic to your side. For now, let's aim for at least 10 times and see what comes after that."
"At least ten weeks, I see."
"You can't back out now even if you want to."
"That's not what I meant. It's just that it would take longer than I expected. I don't know if those who came from Hell will stay still."
"After the 10th time, we'll discuss how you'll be able to leave this place. And about Hell, you don't have to worry about them for now. While they can enter the Human World anytime, Kurotsuchi-san should be able to arrange a better detection method. In addition to that, it shouldn't take long before the Shinigamis learn how to detect the aura from Hell. And besides that, it seems that the Hell residents are only immortal when they are in Hell so this will most certainly be a war of attrition."
"If you say so... How should I enter this... Gigai?"
"Just put your palm on the wide surface beside the buttons. I'll do the rest and you'll lose your consciousness until your body reaches full maturity."
Soifon took a deep breath and set aside her fears before placing her palm on the designated area. It'll be two days later before she wakes up again.