Hiro listened to God's explanation and the fact that he could choose to transmigrate in one of the six recently dead Uchiha in Naruto world.
According to God, there were many parallel worlds and the one which came under his jurisdiction is the Naruto world where currently third shinobi world war has just started. Hiro had no issues because he had already resolved himself that he will need to get used to killing humans from now on. After all he was going to be a ninja from now on who were basically killers by profession.
Hiro was still confused even after God showed him the situation of the six recently dead Uchihas. Three of them had their eyes plucked out from their dead bodies so they were not an option for Hiro. From other three, one was a jonin, and other two were chunin.
Hiro wanted to posses the body of jonin called Uchiha Yami naturally because he would straight experience of a jonin class ninja after waking up in Naruto world. Hiro thought for a while and his confusion fully disappeared because this was after all the best choice. He still needed to confirm one thing from God because it will give him more nice headstart.
Hiro - God, did this Yami guy posses mangekyo sharingan before he died ?
Hiro's tone had unconcealed excitement in it even though he was almost hundred percent sure that it was not the case. After all Yami wont have died if he had mangekyo as the war was only at the stage of small skirmishes yet.
God - You asked a very thoughtful question my son. And my answer is both yes and no.
Hiro was confused but God's answer blowed his confusion away immediately.
God - He only had 3 tomoe sharingan but managed to awaken mangekyo in his last moments as he experienced a lot of despair then. One more good thing will happen if you choose his body because when I purify your bloodline limit, instead of mangekyo, you will straight awaken Eternal mangekyo and I'm sure as a fan of the series , you know its benefits already.
Hiro's mind immediately experienced great shock from immense joy because his luck was too good. He started feeling dizzy but forced himself to stay sane because he would have to make his choice as soon as possible now as it would be a pity if someone plucked the sharingan out when he was feeling joy.
Hiro - I choose this body then. How much time will it take before I awaken next time God ? "
God - No need to worry son. I will accelerate the process using my powers so you will wake up in just about a minute with your soul fully fused with the new body. I advise you to immediately find a secular place after that as it will take three days before your bloodline is completely purified. Your bloodline will be damaged instead if I use more power to accelerate the process more.
Hiro immediately digested the information before smiling. He took a last glance at this God and gave him a deep bow because he may have caused his death but he also gave him a chance of which Hiro can never thank him enough. Hiro also wanted to know the powers of his mangekyo but decided to wait.
Hiro - I'm ready God.
God smiled and waved his right hand. Then a black portal appeared behind Hiro and sucked him inside with great suction power . Hiro just closed his eyes and went with the flow.
......
After a minute , Yami woke up feeling fresh as he checked his new body's condition. There were many slash wounds but all had closed now. Yami thanked God silently for a while before immediately starting dashing away from this small forest.
He had already fused with the body now so would be called Yami from now on. From the memories of this body, Yami understood that he died after confronting a small squad of Iwagakure led by one elite jonin. He managed to kill few enemies before the elite jonin trapped his movements using a earth style binding jutsu and finished him off in seconds.
Yami could feel twitching pain from his eyes and knew that his bloodline must be currently being purified by God's power. He was near borders with Amegakure currently so Yami immediately found a safe location where he could easily hide for three days. Thankfully he had already studied the map of nearby places so had location of a small cave inside his mind.
After traveling for just few hours with his now powerful body , Yami arrived before a small waterfall and walked straight through it ignoring the water pressure. As expected he found himself inside a small cave and immediately sat in a meditative pose. He knew that his innate max pain resistance skill was already activated because he could feel a lot of pain from his eyes but it did not feel uncomfortable to him at all.
After few minutes Yami let out a disappointed sigh out because he discovered that he was an orphan in this life too. He wanted a family this time . Soon his mood became better as he realised that his clan was very nice to him and treated him like a family member. Yami may be an orphan but he had already awakened fully mature sharingan according to them which gave him a lot of prestige.
Yami now had to do a job so he immediately took out a small scroll from his ninja pouch and unfurled it on the ground. He wrote the details of the enemy squad he had faced and wrote a lie that he had escaped using a shoe clone. Nobody would notice his lie as the elite jonin had actually suffocated him to death slowly. That vicious bastard dared to bury him alive. Yami also felt thankful to him though because through feeling despair he now had mangekyo and would soon awaken eternal mangekyo sharingan. The benifits of pure bloodline were even greater than Yami had expected because he could feel that his vision was improving slowly along with his chakra level. At this pace he should have at least double character reserves from before after his bloodline limit is completely purified.
Yami put the scroll on another scroll which had strange sealing formula inscribed on it. It was the formula of reverse summoning jutsu. Yami immediately formed few hand signs and imbued chakra into the formula. The next moment, the small message scroll disappeared with a small cloud of smoke. Yami was completely fascinated as even though he had the experience inside his brain but it was his first time watching such magic with his eyes in reality..