Time travel. This was the idea that had started this ridiculous escapade of mine in the first place. When I was 13, I had been allowed to participate in a time travel experiment to stop a disaster that was to happen at the time, along with my old master.
Long story short we succeeded, and nothing happened after that. It wasn't until 26 years later in the aftermath of the 5th Shinobi great war that I had remembered the incident and took it upon myself to investigate it, with the hope of being able to do something with that information.
Long story short I realized it was a lost cause. The time travel the "Karasuki" offered wasn't the real time travel I was looking for. It didn't change the past. More specifically, it couldn't. There were clearly defined laws that I wasn't aware of when I had been younger, and one of them, as I had learned the hard way was: "Change to the past under the assistance of the Karasuki or any time traveling device that affect the timeline in any way significant, will thus be rendered null."
That is to say no killing anyone from the past, giving important information to people from the past, changing things in a way as to cause large domino effects in the time continuum, etc. And if you decided to be adventurous enough to try (despite getting warned by the Karasuki) it didn't matter because the moment you went back in time to the present, you'd realize that no changes had been made.
On top of that, the more the time spent in the past and the more information you get the more chakra it consumes. Basically, if you learned important information while under the effects of "time travel" there's a pretty good chance of you dying or getting a "rule" placed on you.
This was the reason why most world powers never gained anything as a result of time travel. And the test subjects for time travel experiments who ended up getting important information or who had spent long periods of time in the past ended up either dying from chakra exhaustion, or getting a rule placed on them, which physically made them incapable of doing anything with the information they had learned.
However, I couldn't look away at what would happen if I was capable of pulling it off. And after 6 years of diligent effort into the matter, I finally got some results. I had created the first real prototype for real time travel.