Board Thread:Boruto: Naruto the Movie/@comment-1693281-20160126142458/@comment-25122992-20160201163753

Indra/Asura are the only examples of reincarnation cycle, so by default there's no other examples aside from these two in excistence. Thus the question: why only two of them? Obviously, because they had some kind of unfinished business (i.e. brothers' feud) between them which had to be finished by their new incarnations. Naruto has settled this business by making peace with Sasuke, so there's no need for the brothers to be reborn in someone else anymore. They can peacefully rest in the Pure World for eternity.