Is is conceptually the same as the Chidori, it´s used the same way, they have the same sound and hand seals... you could say that Indra created the Chidori, but given the fact that Kakashi made the Chidori a thousand years later, and that he named it, he is considered the true creator of the jutsu

Saying he was the true creator of the Chidori is not technically correct. Yes. While he was the first to create the practice of using hand signs to initiate Jutsu, he didn't create it. Kakashi was the original "inventor" of the Chidori, which was basically him trying to add Lightning Release to the Rasengan, but it failed and burst out. While Chidori did look like the Lightning Release Jutsu Indra had used, we can assume that it was a whole different Jutsu in regard.

Also take note that the Rasengan, which Kakashi tried to add on to, was an invention by Minato, the 4th Hokage himself. During the time of Hagoromo, since his mother was the first Chakra user of all time, he was already gifted with amazing Chakra control. His sons later on, also gained the Chakra infinity... actually not true. Asura was the prodigy, but not Indra. Asura then "created" the original Rasengan, or rather something that Minato would take and master it into the Rasengan. Indra would probably have no idea about it, and therefore wouldn't know how to use it.

To make simply. Chidori = Rasengan + Lightning Release. Indra did not know Rasengan or the technique his brother created. So no. Indra was not using a technique that predecessors the Chidori in anyway.

Chidori is not Rasengan + Lightning Release. Kakashi made Chidori because he failed, but Chidori did not burst forth from the attempts to combine Lighnting and Rasengan.

Indra was the prodigy, not Asura.

Asura did not create the Rasengan, and whatever technique he did make, Minato wouldn't have taken it. They lived a great many generations apart.

Kakashi created the Chidori.

Perhaps I mispoke. I knew that Chidori wasn't Rasengan + Lightning Release. I only had worded that way because I believed it was to give a better understanding on how Kakashi had tried to create it. When he was training Naruto to help him master the Rasenshuriken, Kakashi did create a Rasengan in front of him. From there, he tried adding Lightning Release to it, but it didn't work and therefore it became the Chidori, or rather the Lightning Cutter/Blade in his case.

When I meant prodigy, I meant it as "freedom of chakra control." Indra didn't have it, but Asura did. So I was referring to that.

Yes, Asura did not create the Rasengan, but he developed a technique that was quite similar to it. If you look at the picture on his profile, you'll see a whole bunch of chakra spheres that highly resemble the aforementioned technique.

@Skywarrior, no, Kakashi's rasengan did not become Chidori when he tried to add lightning to it. He developed Chidori because he failed at adding Lightning to Rasengan. Chidori is not a result of his attempts to combine the techniques. Chidori is a technique he developed separately to make up for the fact that he couldn't combine Lightning and Rasengan.

Indra had way better chakra control than Asura. He was the prodigy of the two.

Asura did that in a filler first of all. Second of all, techniques that look similar are not necessarily similar in creation and conception. Third, there still is no way for Minato to take the technique and further develop it because they lived so many generations apart. Besides, Minato developed the technique when he was inspired by Tailed Beast Balls.