Might Guy!
"As a ninja of Konoha, your favorite blue beast has face a ton a weird situations and dangerous foes in his life. So when I found myself transported to another universe more technologically advanced and had even more powerful enemies then then my own, I took it pretty well.
"After walking around for a few hours, I stumbled upon this group of robots that were rounding up and were going to execute them, and looking up, I saw Brainiac's ship in the sky.
It was only then that the time for questions would have to come later and the time to fight began.
After I managed to take out the group of robots, my heroics didn't go unnoticed as this really fast man by the name of the Flash introduced himself, apparently he saw what how I dispatched those robots, so I decided to ask him some questions that I had as I told him that I wasn't of this world.
"He told me that either this "Brainiac", someone named "Dr. Fate" or Flash's boss called "Batman".
I went with the Flash to the Insurgency's base and Batman explained that it was he who indeed brought me here but due to some technological mishaps, it teleported me to the wrong place and explained the reason why, although it was quite obvious.
Brainiac was invading this Earth and he was going to destroy the planet unless he gets his hands on someone called "Superman", who was currently incarcerated in a red sun prison and Batman brought me here because apparently he's been watching over my universe for a while and he saw what I was capable of with my Taijutsu mastery, the power of the 8 gates as well as the power of youth.
I quickly agreed that I would help stop Brainiac on the condition that Batman would send me back to my universe once the current threat was dealt with so I could fight in the 4th Great Ninja War.
Once he agreed, it was off to stop Brainiac.
Smoke bombing into the ship with what was left of the Insurgency, we were faced an army of Brainiac's robots. They were quite easy to handle because of my experience fighting ninja just even more dangerous then them. Once we were finished taking them out, Brainiac himself came down to greet us.
He told us that he was going to collect this Earth's cities and that my arrival changed nothing.
Oh how wrong he was...
Using my seven gates, I used every move I could think of to hold my own against this genius alien, cause fighting him was really difficult. I could tell that he was fighting to kill me every time that I briefly stopped to take a breath. And with each hit I took, I was so tempted to open the eight gate, but I refused not to as I knew the consequences of doing so as my father died opening all eight of them.
I used such techniques such as my classic Dynamic Entry to the gravity defying Primary Lotus to the fiery Morning Peacock technique. Heck, I even used the island destroying Daytime Tiger to finally knock him out.
Once Brainiac was out of commission, for now anyway, Batman held up his end of the bargain and I was sent back to my universe.
Once I was back in the Leaf Village, I told the Hokage, Tsunade and my eternal rival, Kakashi about what happened and where I suddenly vanished off to, at first I thought neither of them wouldn't believe me but after seeing the state I was in and answering some questions, they believed me.
As the war began, I was currently in the hospital for the next six weeks recovering from beating Brainiac.
Once I got out, I was enlisted into Kakashi's unit alongside my pupil Lee and Kakashi's pupil Sakura. It was time for me to help stop Madara and his Akatsuki from capturing Naruto and this other Jinchuriki named Killer Bee in order to enact their Infinite Tsukuyomi plan.
Time for the noble savage of the Leaf to ignite the flames of youth once more!