“I´m curious.”
These two words, when Senju Tobirama spoke them, make the entire Senju compound fall into hysterics and stay at least twenty feet away from his lab and him, until he once again emerges from his very own room, that might as well be his second home with how much time he spends in there.
He has to admit that he is in fact very proud of that reaction.
It took him exploding Touka´s work, blowing up the garden in their backyard, temporarily henging Hashirama into a woman for two weeks, his water jutsu coloring anything that it came into contact with bright orange and very much accidentally temporarily transforming a man who had tried to assault one of the female servants in their household into a squirrel, which he recovered from three weeks later.
He doesn´t regret the fact that the buck teeth remained.
Despite all these weird occurrences, many people still think that when Tobirama makes jutsu, they´re meant to be used as weapons.
In some cases, they´re not even wrong. The water dragon jutsu for example was created in one of his mad scientists fits, when he desperately tried to come up with something that could go up against the annoyingly large fireballs that Izuna used against him.
When he finally succeeded and the dragon managed to swallow one of Izuna´s fire balls whole, Touka confessed that she was almost gutted, being too busy laughing at the Uchiha heir´s face expression to properly block.
The other water jutsu he came up with had very much the same purpose. Countering the fire affinity of the Uchiha in order to survive on the battlefield at least one more day.
The reality seal he came up with was also meant to be a weapon, or rather a defense. It tuned out genjutsu to some extent and has helped saving many lives so far.
But not all of his jutsu are weapons.
Tobirama´s hiraishin seal was not meant to be a weapon at first. He´d come up with it when he had been infuriated with Hashirama once again – a common occurrence. No one in the Senju compound was surprised anymore, really – and had set up a barrier seal to keep his brother out of his room.
( The reason had been Hashirama suing mokuton to transform Tobirama´s bookshelf into a bonsai tree, with all the books still on it. Another instance where the Senju collectively stayed away from him, because once he got loud when angry, they knew he was not to be disturbed. )
He had been working on seals again when out of nowhere it occurred to him that while the barrier kept anyone from coming inside, it also kept him from going outside.
Which, really, was common logic. But once Tobirama started to think about it, he tried to find a way to go around that.
A technique basing off of the shunshin and the basic concepts of a summoning, invented because he wanted to keep his brother out of his room for turning a shelf into a bonsai tree. No such thing as the desperate need to improve his speed, since Tobirama was already very fast even without his teleportation jutsu, but an invention coming purely from pettiness.
The other jutsu that was not meant to be a weapon – his proudest, but also his most disgusting creation – was the edo tensei.
Thirteen.
That´s how old Tobirama was when he came up with the concept of the jutsu.
It was never meant to be a weapon. But when he stood for hours above Itama´s grave, staring blankly at the flowers that he and Hashirama had arranged around it neatly before, something in him snapped.
And like the foolish child he was, Tobirama believed that he was above nature´s laws. That he could, and would, bring Itama and Kawarama back to live.
He had missed them. So much.
So goddamn much.
Hours on hours, whenever he was not on mission, Tobirama would sit in his lab, eyes trained on the infinite number of scrolls before him, written with messy handwriting, for his hand was beginning to tire out even worse than after a harsh training, and his vision was beginning to swim from all the scrolls and ink before him.
He wouldn´t eat, wouldn´t sleep, not until Touka, the only person aside from Hashirama brave enough to enter his lab without his permission, would come inside and literally knock him unconscious.
It didn´t stop him.
He was up and about the next day, hands shaking with how much he was focusing on his work.
And finally, finally, after what felt like eternity, it was there. The jutsu had been created.
He´d tried it with a cat first. His cat.
Hime, who had died only two weeks prior.
He´d used a chicken kept for meat and tried to call the soul of his cat back into the body of it. It worked when he died, and all he had done was stare at it blankly for hours again, tears threatening to spill but never quiet falling down, as Hime was purring and rubbing herself against his outstretched, numb hand.
He doesn´t know what exactly happened that day. He doesn´t know why Hashirama had come into his room in the first place, but when his elder brother had come inside and had seen their cat, scars – cracks - running over her face, yellow eyes tinted a deep black and alive and moving against his hand, he´d thrown up, eyes wide and horrified.
Tobirama hadn´t understood his reaction that day. This was good, was it not? Itama could come back too. Kawarama could come back too. Maybe even his mother.
It took Tobirama years after the incident, when he once again found the scrolls he had hidden for Hashirama, while not understanding his reaction, still respecting it and his wishes, for him to realize just what he had done.
Just what he had been ready to force the souls of his brothers through for his selfish desire to have him back.
It took him years to realize the consequences of him trying to mess with nature´s law.
Years to realize that no matter how hard he tried, he would never be able to bring back the dead to life, no matter how many seals he sued and how much work he put into it.
It was only when he had snapped out of his grief, mostly, that he realized he wouldn´t wish this kind of prolonged existence on anyone.
He´d locked himself in his lab the following day, and no one knew what was the reason or it this time. When Hashirama had tried to check on him and forced his way inside, sensing that something was wrong, he could find Tobirama with that blank stare once again, but this time staring at his hands, horrified with the thought that he had created something like that.
When Hashirama looked over to what might have caused his disassociation and found the scrolls, his expression pinched, a look mixed with thousands of emotions passing over his face, before he quickly stored the paper´s away.
Not disposing of them, because no matter what Tobirama would create, it was something that he made himself. No matter how repulsive it might be, it was his creation, his work and his mistake to learn from.
For all that his elder brother was called the god of shinobi, sometimes Tobirama was too smart for his own good. Too much genius that was in that brain of his, that sometimes made it hard for him to see the human aspect of things before the logical one.
He´d left Tobirama in his room that day, staring at his hands completely still and silent.
The next day Tobirama had been out of his room, face set with determination and deep regret.
He´d apologized for what Hashirama had seen, but admitted that no matter how repulsive it was, he would never regret the reason he invented it for. He also assured him that no matter how perfect the reanimated bodies were, he would never use them in battle.
Not all the jutsu Tobirama invents are meant for battle. Not all of them were good jutsu either.
The edo tensei no jutsu had been neither.
But all of them were certainly what made Tobirama the person that he was. And no matter what, he was naturally a person whose curiosity could never be stilled, not could his thirst for knowing the how of things.
Still, this was Tobirama.
This was his legacy.