The Rasengan

I hated how they did this with most Jutsus that were cool. They had this awesome jutsu that took 3 years to make and then someone else does it in like 3 days like piss off. The story around the rasengan was the awesome 4th hokage made this crazy hard justsu that gets outdone by a loser Boruto. Same with Chidori, it was said it could be done once or twice a day by the 6th Hokage but Sasuke just spurns it at will.

On another note, we can say the new generation always surpass the previous but the conclusion is Minato created the rasengan.... Naruto used kage bushin and Boruto used scientific ninja tool....Minato did the real deal.