Izuna walked into his office. Nothing about the Ootsutsuki was to be taken lightly. Those damned guys could destroy entire planets without breaking any sweat. If someone from them actually persevered to achieve new heights, gods save them all.
He sat in a meditative stance. He closed his eyes and concentrated on the past. He opened his eyes and he was seeing into the past. This was an ability only he possessed. He gained it during the massacre. He waved his hand and time rewinded in front of his eyes. He saw everything from the beginning of Konoha to Kaguya. The farther he went, the more he saw of his Ootsutsuki lineage. He knew he was a direct descendant of Kaguya but he needed to know farther, he needed to know if there was any in the Ootsutsuki clan who would actually persevere.
He went backwards in time. Soon centuries became millennia, millennia became millions of years, millions became billions. Five billion years into the past and all the Ootsutsuki are just like Kaguya and her clansmen during her era. He went further back. The Ootsutsuki empire started to grow smaller. Their reaches stooped extending to the entire universe.
When Izuna saw far enough into the past, he saw the birth of the Ootsutsuki clan. He stopped and went ahead slowly.
He saw quite a few great wars. What he saw made him shiver in utter fear. All of the Ootsutsuki used to persevere once upon a time. If even one of them got their hands in a single chakra fruit... It would be the death of everything.
He then saw two Epic Wars in the planet followed by a long term cold war in the planet followed by another epic war, all in the span of a century. The last one destroyed almost half of the population. One man rose up the ranks of the clan and bound them together. He fit the description Naruto gave for the Ootsutsuki in his dream. 'But why would someone so far from the past cone in Naruto's dream... Hell, how can someone live for a billion years... I have seen Ootsutsuki lives. Even the strongest don't live for over two billion years! No one should even live for that long...'
The Ootsutsuki who matched Naruto's description was named Raijin. He favoured dictatorships above everything else. He had lost everyone he cared about to the war he had just fought. Raijin was a broken man after the war. He had lost his brothers and sisters to the war, his wife and children gone for good, all for the sake of victory on one planetary war. For a simple war between two factions, one that wanted to breed the children using technological way and one that did not. Raijin lost everything he held dear for this petty argument between higher ups. He was pissed off at them. He started his own gang against corrupt officials who looted the hard writing commoners for such petty shit.
The higher ups didn't care about his group until they saw that it was growing. Thousands sympathized with Raijin and thousands more shared the same fate as him and knew entirely of his plight. He was also the first being to manifest the Rinnegan and the Tenseigan. He eventually succeeded in assassinating every corrupt official on the planet. He was still not satisfied. He was not at peace. His broken heart would never find any solace until his death.
Raijin felt that no one else should undergo the same fate as he did. He knew that there were other planets out there and that they would face similar problems as his did.
His ideology was simple. Conflict breeds war, war breeds death, death breeds hatred, hatred breeds conflict. It was truly vicious cycle. He made it his goal to end this cycle.
His method to end this vicious cycle came in the form of the Mugen Tsukuyomi, the infinite genjutsu. A world where everyone got what they wanted... A world without hatred, a world full of happiness.
His planet was not the only one blessed with a chakra fruit. His planet was not the only one that ate it. The residents of other planets did not like intruders trying put them in a genjutsu. Raijin did not take well to this. So he changed his method.
He now made it his goal to eradicate the fourth of the population and put the remaining in genjutsu.
In this quest of his, he found the mighty dragons and formed a contract with them. He became a completed and fully realized Dragon sage.
He forged his weapons by diving into the heart of a black hole and then harvesting the singularity in its center and converting it into a weapon of mass destruction.
He absorbed any and all chakra he could find in the part of the civilization he eradicated. He absorbed any and all Rinnegan, Tenseigan, Sharingan and Byakugan. He became so strong he was capable of controlling an entire galaxy super cluster on a whim.
He became known as Raijin of the ten thousand Rinnegan!