Tobi was a stubborn prick. That was the common sentiments of an entire world, and the man knew that himself. He had kept himself alive for years, unwilling to relinquish his dreams of world conquest. Creating convoluted plans and executing them with near flawless precision and accuracy was the man’s driving force, the only way he could keep his grand ambitions fuelled and alive. Even when the Fourth Great Shinobi War he started to accomplish his Moon Eye Plan failed in its objective, he persevered. He didn’t give up on subjugating the world; he just gave up on that particular plan. Time was no issue to the quasi-immortal man, who could outlive even the most resilient and healthy Uzumaki.
Speaking of Uzumaki, Uzumaki Naruto was another one of those obstinate bastards. This was usually the term his enemies and sometimes his friends used to describe him, given that he had a reputation of never giving up, even when the odds are heavily stacked against him. He never stopped fighting, never stopping giving his all to protect his homeland and his precious people. It resulted in the love hate relationship that Uzumaki Naruto shared with Tobi, one almost identikit to the respect cum hatred that the Uchiha had for his Senju counterpart. It was why Tobi deliberately targeted all of Naruto’s friends and family. Tobi used the excuse that he wanted to break the younger ninja’s spirit; secretly, the elderly Uchiha wanted to goad Naruto to his full potential before crushing him in battle. The members of the Uchiha Ichizoku always believed in their superiority, and Tobi was no exception to the rule.
Their clashes had become legendary in the devastated ninja world. Tobi would formulate some complicated, dastardly plot, and Naruto would blow it to smithereens in a climatic fight with the aging Uchiha. It was getting tiresome, but Naruto was not going to shirk that responsibility. Their battles have ripped the landscape apart, and usually after Tobi’s evil machinations had destroyed most of the area already. The collateral damage was ridiculous, so much so that the world had reverted back to the days of individual clans fighting for supremacy. Naruto never could manage to kill his slippery nemesis, which always led to craterisation of another spot of civilisation.
Another climatic fight was on the cards, and Naruto had prepared well. He had Tobi on the ropes right from the beginning, planting a Hiraishin seal on the man and forcing Tobi to teleport constantly in order to avoid being eviscerated by a Wakusei Rasengan. Edo Tensei warriors needed time to recover from that attack; Tobi was pretty sure even he would die if he got hit. Use of Susanoo was pointless, not when it was obliterated with a volley of Fūton: Rasenshuriken right off the bat. Any offensive moves were nullified immediately with Hiraishin, which the blond had planted seals of all over the battlefield. And it didn’t matter even if he lost those, seeing as he could teleport to Tobi and avoid the damage instead.
Kurama was able to resist Tobi’s Sharingan too, which made the fight twice as difficult. When you had a giant demon fox smashing up the area with wild abandon, it was tough to avoid that comparatively tiny man teleporting near you with a mortal jutsu in his hands. Tobi had to expend quite the large amount of chakra to suppress Kurama, and then Naruto just pulled the Kyūbi back into his seal and turn it into a colossal waste of chakra. It irked Tobi greatly, being unable to break out of the stalemate; he always had something to pull out against Naruto, but it appeared that the blond had all the counters this time. Not even the Rinnegan fazed the Uzumaki; he just raised his hitai-ate covering his left eye to reveal the Rinnegan he had evolved from Sasuke’s Eien no Mangekyō Sharingan. It didn’t matter that he wasn’t an Uchiha or Senju. His well-nigh inexhaustible chakra reserves coupled with the distant blood relations the Uzumaki had with the Rikudō Sennin made the Rinnegan a viable dōjutsu for the cerulean-eyed man to use against another Rinnegan.
Tobi was glad Naruto didn’t have access to Mangekyō techniques, or he’ll be in even deeper shit. At least he knew the limitations of an implanted Rinnegan; the Mangekyō was far more versatile in its options, given that its plethora of techniques varied in effect between users. But it was a losing fight Tobi fought, as his chakra depleted quicker and quicker, and he got no closer to killing the annoying blond Uzumaki. It only took one slip up to lose it all, and the Uchiha eventually obliged, his reflexes dulled by the harsh physical and mental drain of the battle. An incoming Fūton: Rasenshuriken distracted him from the threat of an onrushing Naruto with Wakusei Rasengan, and it was over.
His innards screamed in agony as he was torn to pieces by the conflicting rotational forces of the Wakusei Rasengan, spraying crimson blood all over the barren plains where the fight was taking place. His blood soaked the ground beneath him as Naruto grimly held the Wakusei Rasengan, forcing it to bifurcate the deranged Uchiha in a very messy manner. Tobi gritted his teeth, unwilling to concede defeat in such an ignoble manner. With a last defiant roar, he dredged up the rest of his remaining chakra, forcing it to his eye.
The telltale swirl of Kamui was almost lost in the whirlwind of chaos that the Wakusei Rasengan caused, but Naruto did notice it. Letting go of the chakra in his hand, the powerful Rasengan variant collapsed explosively, practically evaporating Tobi. A quick Hiraishin was not quick enough however, as Kamui activated, absorbing everything within a twenty feet radius into the alternate dimension of the recently deceased Tobi. Combined with the Hiraishin, which made liberal use of space-time warping to achieve controlled dimensional travel, it was a recipe for disaster.
The ninja world would never see either Tobi or Naruto again. It rejoiced.