How exactly were Madara and Obito able to control Kurama?

Question

Madara and Obito could control Kurama with their Sharingans. My question is how exactly did they do it? What is required to control this beast? Is the Sharingan enough to do that? Can they control any other beast with the same technique?

I remember Kurama once said Madara's chakra could summon it, but how was Obito able to summon and control it on his very first attempt? There's no way he could've practiced it because it was sealed inside Jinchuriki since Madara's defeat against Hashirama.

So how exactly were Madara and Obito able to control Kurama?

Answer 1

Okay, in order to understand the answer, you need to understand the links between the Tailed Beasts, the Uchihas and the Senjus.

The Sage of Six Paths was powerful enough to subdue the Ten-Tails, store it within himself and even split it into the nine Tailed Beasts. His two sons, Indra (whose descendants formed the Uchiha clan) and Asura (whose descendants formed the Senju clan), inherited his powerful chakra and also his power to control the Tailed Beasts.

Therefore, members of these clans who had evolved to a certain upper level like the Mangekyo Sharingan (Madara and Obito) and the Sage Mode (Hashirama Senju with his wooden dragon) also inherited the Tailed-Beast-controlling abilities which originally belonged to the Sage of Six Paths Hagoromo and was later passed on to his descendants.

Answer 2

To control nine tails, First hokage's wood style justsu or powerful sharingan will need. Madara has Magekyo sharingan and First hokage's cell, so he absoulutely can control nine tails and also Obito.Even nine tails can be controlled, another tails beasts'll be easy to control.

Answer 3

Sharingan give the ability to control the others with their eyes. That how madara and obito controls the nine tails. Coming to first hokage he developed a wodden style jutsu to control tailed beasts. That jutsu draws tailed beast energy and emerges as a forest leaving tailed beast without chakra to fight.

Answer 4

Sharingan has the ability for Hypnotism. From naruto wikia site

More advanced Sharingan users can take the hypnosis ability even further to the point where a powerful summon like Manda or even a tailed beast may be controlled. It has been stated by Madara Uchiha that the beasts were slaves to those with the blessed eyes.

So using this ability both Madara and Obito controlled Kurama.

As for as the summoning concerned... (This my speculation only and I don't have any source to backup)

The tailed beasts are not living things and they are almost mere tools. They don't need blood contract to be summoned.

Kurama was summoned in the same way Ten Ten summoning her ninja tools. When she first tried summoning she didn't made any contracts but she summoned some tools. So the same way Kurama was summoned by Madara and he thought the trick to Obito too. But only catch is it needs a lot of chakra to bring out the beast.

Answer 5

Sharingan user can cast a genjustu or protect against one. This has been said since chapter 003 (First Team 7 mission against Zabusa).

There are no limits on whether it is people or bijuu. In no chapter, the limits are stated so why assume there are limits. Limits depend on user's proficiency of sharingan.

Answer 6

The Sharingan specifically the mangekyo has the ability to put any being into genjustsu, that includes even tailed beasts, as it is inherited from the sage of six paths,the one who created them. As for obito he even had hashirama’s cells so a genjutsu to control even the quibe wasn’t an issue. The summoning contract is more or less to transport kurama and is not something that requires a formal contract like with toads,it is like shinobi summoning tools from scrolls,like ten ten.