What is the primary principle of controlling Jinchuuriki? I can think of two possibilities:
- Control on hatred/negative thoughts;
- Will and wish of tailed beast.
Killer Bee could easily get in a good relationship with Hachibi. We can recall the Falls of Truth incident of Bee, where he could easily pass it in a second, because he didn't have any hatred about anyone around him in his heart. So is it because he had suppressed negative thoughts, hence he got his tailed beast under control? Or is it because Hachibi himself is a really good guy, who is broadminded enough to lend his chakra to Bee?