Even if Daniel could survive the explosions, leaving the things around the room behind didn't sit well with him .
He needed to find a way to avoid explosion burning down everything. He somehow had to confine the explosion or stabilize the source.
As Daniel was trying to come up with a solution, reckless idea came to his mind. Since he didn't have much time to think, he decided to give something a try.
Even if things went wrong, he was leaning on earth spear to keep him from critical damage.
Daniel approached Arata and pierced his chest with the threads. He started performing the Jiongo in reverse. Carefully, he infused chakra in scientist's heart, while simultaneously tried to keep his chakra contained inside the body. It begun to somewhat work. Chakra volume was still rising but it was getting more stable under his control.
While stabilizing the chakra fluctuations, as a precaution Daniel concentrated on his chest where his hearts were located. His back opened up and he released one of the spirits from his body. Immediately, upon Daniel's orders it dashed outside of hideout. It would stay in a safe distance away and if the explosion occurred was ordered to head back inside. Then it could revive him by sacrificing itself. Daniel grinned, now he didn't need to worry about the explosion and could take his time to find out if something special came out of this.
Slowly, chakra fluctuations stopped increasing and Daniel gradually reduced it by further containing it as he kept infusing his chakra into the old man's heart and through it, into his chakra system.
It took time to reach noticeable progress and after a while familiar process started unfolding before Daniel.
First the scientist's skin, followed by muscles and bones turned into the threads. Time it took was much longer than it took earlier with the guards. Arata wasn't even ninja, which meant potion might have been a catalyst for it. Daniel recalled that potion meant to increase the talent of human body. If that was the case, chakra system should be main target for the research. By stimulating it, potion would permanently enhance shinobi's chakra volume. But that was too much of a general gist of it. What really mattered was how Arata went through achieving it. Daniel glanced at the table where Arata's handwriting was placed. That could be useful some day, something he would look into after the war. But now he focused back on the present.
An [F-grade] heart shouldn't have taken so much time for a transformation. It took about an hour, which was lot longer than the guards. Daniel was curious about result. It made sense that since it took more time, the spirit would be stronger too.
As chakra fluctuation begun decreasing, a blob of tendrils was formed that was result of mass of threads merging and twisting around the heart. Daniel observed it patiently. It had lightning affinity, which was a nice surprise. This affinity was rare outside Kumogakure. Unfortunately the heart also possessed weak vitality and talent.
Despite this, Daniel could feel something mysterious buried deep in this spirit. He took out a sealing scroll and summoned a mask with an yellow nose in the center. This was one of the Jiongu masks, designed specifically for a lighting affinity. But unlike previous ones that he used, this one was made by Kakuzu.
"An [F-grade] huh... I expected more"
Daniel suppressed his disappointment. He just had to figure out what was special about this one. He felt connection between them to be more clearer than previous masks that further convinced him to pay extra attention to this spirit.
As placed mask on top of the blob, the same process begun to repeat again. Daniel waited until spirit stabilized its form. But before he could check the spirit's functions, something unexpected happened.
"…Hello?" Daniel heard voice echo inside his head.
Daniel widened his eyes. Was this supposed to happen? Had someone else discovered him or was this another new ability of the Jiongu?
"What happened to me boy? Is this your doing?" The voice said in his head again.
Communication was telepathic. It was similar to signals other masks could send, but this was more advanced, it first time he heard coherent sentence through the connection. The other two spirits communicated with just intent and couldn't formulate words.
"Is that still you old man?"
Arata, or at least, entity in front of him that had the similiar aura around him, looked down on it's body.
"Hmm...I'm not sure what I am anymore." His threads morphed into various shapes and finally stopped as it took shape of hands. "I should be dead. Exploded to smithereens. What happened? How did you stop it?"
" I used my jutsu on you to stabilize your chakra. It's also why you're looking like that. Though I wasn't expecting you to survive." Daniel remarked.
Arata nodded in understanding. He walked over to table where he was working on the potion and looked down at empty capsules, placed all over the place. "By the way... I don't remember hearing your name. What shall I call you?
"Dan would do" Daniel said.
Daniel decided against borrowing Kakuzu's name. He didn't want to use it unless it was necessary. His no longer was in the world he was born in, he had body that wasn't originally his and even his mind wasn't left without a change. Loosing his name along with it didn't sit well with Daniel. Then again, origin of his full name could be bothersome to explain. So he decided on using it's shortened form.
"So Dan… what is the plan? Where will you go next?" Arata asked.
After observing a while, Dan could deduce few things about anomaly standing in front of him. If normal spirits were like robots, this one would be akin to A.I. If original Arata was dead or standing in front if him wasn't clear to him yet. But spirit would have to either going to stay under him or he would have to kill it. Unlike with regular spirits, he didn't have this one's full loyalty. Which was enough to warrant a concern. He wasn't sure he could trust him, or it for now.
"What about you doc? What will you do?" Dan asked back.
"Don't ask pointless questions lad, you don't seem to be planning on leaving me alone anyway are you?" The spirit of Arata shook it's head in annoyance. "I don't even know specifics of your jutsu. Do I look so reckless to you that you think I'll run away?"
"Yes you do old man. I need some guarantee that you won't stab me in the back." Dan said. Using [F-grade] spirit for combat wasn't viable. well, so he wasn't sure how useful he would be. But then again, Arata was originally a scientist, not a fighter. "Well, I'll figure something out. For now, pack your things. We'll be heading to Land of earth first."
"Oho? You're planning about visiting that island already? What is so important there that you're in such hurry?"
"Don't be too impatient doctor, you'll know in time. Before that, we'll need to check what happened to you properly." Daniel said. He then tried to order the spirit to move next to desk. It followed the order immediately.
"What the... hey what's going on here Dan? Are you doing this?" Arata asked. His body moving without his will.
"That's one thing confirmed I guess..." Daniel remarked as he tried to observe how the connection worked. "So doc, what was that about?"
"...hmm? Oh you're asking about the potion? Well... it just didn't turn out the way I intended. Just so you know lad, I wasn't trying to blow you up."
"No old man, that's not what I'm asking. What I'm interested is the cause. What triggered the explosion?" Daniel asked.
"Hmm... this was first time this happened. I don't know much without conducting experimentation few more times. There were incidents when potion caused chakra system to fry, but never explosion. Chakra became so dense it started materializing. It was damn painful too. Nothing I've ever experienced before and I've been through quite number of incidents. My body was paralyzed and I couldn't even make a sound. It was torture. Then again, to dig deeper, this requires trial and error. I need human subjecys. The more the merrier. I'm glad I've written down the formula because I don't think I could make it again from the scratch without wasting resources. Still, this requires more research. We need to-"
"Okay, enough, calm down a little doc. You're going down the tandem on random things. We aren't going to do more experimentations for now. I just wanted t confirm the cause."
"Right. There was mistake that slipped through somewhere that resulted messing up the chakra network. But come again, what was that thing about no more experimentations?"
Daniel ignored the scientist, who was complaining in the background and gave the events more thought. Even if potion was a failure, it still had it's effects. It had somehow resulted creation fo a sentient spirit. Which was already impressive enough. But Daniel felt there was something else to it. Something like a bottomless well was in the heart of the spirit. Daniel felt annoyance for not being able to figure out the cause. Nevertheless, exploring new abilities of the jutsu was an exciting prospect for Daniel.
Daniel looked at Arata. Since the old man had taken the form of the lightning spirit, he was tall, easily two times the size of Daniel. He had broad, overstretched shoulders and relatively thin appendages. Shape of its body was similar to reversed triangle and at the end was a long tail. Currently, Arata was closing and opening his claws and observing changes that Jiongu had caused.
"How are you feeling?" Dan asked
"Well… how do I say this... as weird as it sounds, it has been a long time since I felt this alive. All the pain and discomfort of my old body is gone." Arata said with awe.
"That said... even though my sight has improved, my sense of smell has disappeared. completely That will cause some problems. My sense of touch is somewhat off as well lad. It feels like I'm wearing gloves that I can't take it off."
"Hmm. You'll get used to it. I can modify the mask's seal somehow if necessary, but it'll take some time to figure that out." Dan said. "How's your chakra?"
"Oh, it has increased significantly compared to what I had. But it shouldn't be a surprise, my old body didn't have much chakra anyway. I'm not sure if it was because of changing my body into this or because of the potion. Maybe combination of both. It's still nothing impressive compared to average shinobi. I'll need to study the cause of this more." Arata said thoughtfully.
Dan realized that scientist was going to go on another long monologue about experimentation. He picked up random iron rod laying on the ground threw it at Arata.
"Catch." Dan said as he threw it and Arata looked at the rod, now placed between his claws, with confusion.
"Now what?" Arata inquired.
"What else? Crush it. I want to test out your strength."
Arata hummed in realization and tightened the grip. After few second of struggling to split it in half, he stopped on the endeavor and threw it back to Dan.
Dan inspected the rod. There were noticeable imprints that were bended the rod inward. It was impressive, for a human. But for a four-meter-tall monster? not so much.
"I'm noticing the look of disappointment from that face Dan. Keep in mind that I haven't used chakra to sharpen the claws or cutting it wouldn't be much trouble." Arata explained and as a demonstration swung his claws towards the wall.
Dan noticed that slash had left behind deep cuts on the wall's surface. It was better result, but with that speed the spirit would only be able to fight chunins at best.
"Dan... You aren't planning on making me fight are you?"
"...?"
"Seriously?"
"What seriously?"
"Stop messing with me lad. Are you really planning on forcing an old man to fight for you."
"I'm not sure yet, you won't be able fight in close combat, but I want to test out your ninjutsu. You might have talent, who knows. And also, look at yourself doc, you aren't exactly old man anymore are you?"
"..." Arata stared speechless at Dan for a while, then sighed. "Fine. I always wanted to be a strong shinobi as a young man. Maybe I should indulge myself a bit."
"Well, isn't that is just perfect, old man. Wel'll test out what you can do during the travel. Let's go, we have someone to pay visit for."