Naruto Thread (Spoilers For Sure)

But the problem is, it took naruto how many years of bargaining with the fox and everything during virtually his entire life to convince the Kyubii to let him use its chakra at will?

Minato literally had the seconds/minutes between dying from the dead demon seal and the time it took to get from orochimarus summoning party to learn how to use the chakra.

It's because of the badass clause. Some people are so god dam badass that there is no explanation for how they can do the amazing things they do except that they are badass.

Minato is definitely one of such people.

This answer will have to do. I doubt this will be developed further than those lines between Naruto and Kurama, "My old man is pretty badass...", "tell me about it...". In the end Minato is as much of a genius as Itachi was or maybe even more? So its not totally far fetched for him to just be "badass".