Despite being regarded as a shonen classic, Naruto contains a plethora of plot holes throughout the story. Perhaps the most notable is Madara Uchiha, a divisive villain who some admire for his unparalleled strength while others despise for being easily manipulated into killing thousands of people for what he believed to be the greater good. The fact that Masashi Kishimoto created a brilliant character like Madara, only for him to be played so easily by Zetsu, is perplexing in and of itself, but the plan to cast Infinite Tsukuyomi is riddled with so many logical inconsistencies that his reasoning eventually stopped making sense.
It would have made more sense to portray Madara as a completely evil person intent on simply destroying the world; for better or worse, giving villains a tragic backstory and motivation in order to elicit sympathy from fans is a series trademark. Despite the fact that this character has a slew of issues (including the fact that he was not even the series' final villain), his reanimation is even more absurd. In fact, it could be the series' biggest flaw.
How Did Madara Rise From the Dead?
Kabuto Yakushi performed a forbidden Jutsu to revive Madara and thousands of other fallen Shinobi. Even in a reanimated corpse, his strength was so immense that entire armies of Shinobi were no match against him. Then, to make matters worse, Madara forced Obito to perform the Rinne Rebirth Jutsu, reviving him completely. He not only regained a living body but also took back his Rinnegan, making him the most formidable foe in the entire war zone. The combined strength of the Five Kages couldn't put so much as a scratch on the strongest Uchiha in history.
What Was the Plot Gap, and How Was It Closed?
Looking back at all the characters who died and were then reanimated using a forbidden Jutsu, it is clear that their reanimated versions are at the same age when they died. However, Madara was well over a hundred years old when he died, but he was reanimated in the body of his younger self (approximately his 30s). He was then revived, making him stronger than ever. Madara also had the same Rinnegan eyes he awakened shortly before his death.
Had Madara been revived in the body of an old man, it stands to reason that he wouldn't have been able to cause so much destruction; however, in order to make the villain seem more intimidating, he had to be in the body of a young man. Since the series never explained this unusual phenomenon, it is reasonable to consider it a plot hole -- and a major one at that.