Naruto fans unanimously agree that Madara Uchiha was indeed a force to be reckoned with. Even in the new era, his name can bring terrible nightmares to everyone in the Shinobi world. During his lifetime, Madara was the only member of his clan to awaken the Mangekyo Sharingan and attained mastery over it in little to no time.
With his Mangekyo Sharingan, he was able to conjure a Complete Body Susanoo, which was capable of dealing with powerful attacks, making even Ultra-Big Ball Rasengan look weak. Madara's most powerful feat was his ability to control Nine-Tails with ease.
However, when Madara conjured the Nine-Tails: Kurama with a proper Summoning technique, it made every fan question how he could do that with a Tailed Beast.
How can Madara Uchiha summon the Nine-Tails in Naruto?
After subduing the Nine-Tails by putting him under his Genjutsu, Madara formed a Summoning Contract with the Tailed Beast without the latter’s consent. It was also noted that all summoners have to use their blood to conjure their animals, but Madara had no need for that, as he simply put his hands on the ground to summon Nine-Tails.
In Naruto, a summoning contract can only be formed with majestic creatures who possess powerful chakra and are bound to serve their summoners. However, Madara Uchiha was the only exception in the storyline, who disregarded the fact and tried to create his own technique by combining his Genjutsu with a transportation Jutsu, which is likely to be a Body-Flicker technique.
Although animal summons are bound to obey their summoners, they too have free will. Animal summons can communicate and assist their summoner on the battlefield without the need to be controlled. However, Madara had to control the Tailed Beast almost all the time, like a puppet, even from the farthest distance.
Even the Nine-Tails was scared for his life by Madara’s hold. Despite being a physical manifestation of Chakra himself, he could not manage to break his Genjutsu. Even after his reincarnation, Madara again tried to summon Nine-Tails, but it was sealed within Naruto, which is why his summoning technique became useless at the time.
Not all Shinobis in Naruto are capable of this feat, as it would require the person to possess a tremendously large reserve of chakra. They should also be exceptionally strong in Genjutsu, as not every Mangekyo Sharingan user can accomplish such a thing. Controlling the Tailed Beast takes a heavy toll on the user's eyes.
The only reason Madara was able to control the Nine-Tails effortlessly was due to his Eternal Mangekyo Sharingan. From the over usage, his Mangekyo Sharingan deteriorated over time and also made him blind, which is why he unwillingly took the eye from his brother’s corpse to awaken the Eternal Mangekyo Sharingan.
Even Obito, who is regarded as the greatest lat bloomer ever, managed to summon the Nine-Tails to attack Konoha. However, unlike Madara, Obito required only one eye to control the Tailed Beast.
After he was saved by Madara during the Third Great Ninja War, he learned all the techniques, including forming a contract with Nine-Tails, which made him one of the deadliest forces in the series.