Board Thread:Boruto Discussions/@comment-33255203-20171004210031/@comment-734582-20171007115552

Elveonora wrote: I think Kisame was called a Tailed Beast without a tail for more than one reason. First, enormous amount of chakra. Second, his semi-animal/monster appearance. Third, his ability to merge with Samehada to become an actual shark monster. True. But madara only weakly implies that Tsunade's seal contains a massive amount of chakra (he implies it's Hashirama-levels), but nobody goes on to say that she has biju-levels of chakra in her seal. Madara and Obito were able to fight comparable to a Jinchuriki, but nobody said they had biju-levels of chakra.

It's this weird thing where only occasionally such comparisons get made, and once made everyone else that matches it is never mentioned.