Naruto and Bee take this although all the previous comments say otherwise. You didn't claim they were edo so i'm not going to assume they were supposed to be edo. Naruto over Nagato at his prime, if eight tails Naruto was able to crawl out of chibaku tensei while Sage mode Naruto was able to defeat the pains, then I can only look at it in this way; Current Naruto wins. Naruto in BM is extremely quick and can transform into Kurama at will as well as make KCM and Sage mode clones, having that said if he made two sage mode clones to take on the 6 paths of pain they would win, if he didn't use 6PoP then it would be even easier for Naruto and Bee. Naruto makes 1 KCM clone and two sage mode clone then transforms into Kurama. Nagato uses Chibaku tensei, which would be countered by a TBB or multi TBB easily. While Nagato is concentrating Naruto could have the clones go in close combat with Nagato while one sage mode clone throws WRS, so this would be an easy fight for Naruto since his clones may even have a chance of winning, if Naruto went in the fight then Nagato has no chance since shinra tensei wouldn't even work, as it didn't work against an 8 tails KM. Naruto has way more endurance and chakra as well.
itachi vs Bee would be more complicated. Itachi can't use genjutsu since Bee has already shown he can use Bee to have him disrupt his chakra, meaning Itachi's genjutsu is useless, which he would find out after he had wasted chakra creating a genjutsu. Bee has been able to withstand Sasuke's Amateratsu which is no different then Sasuke's Amateratsu. Bee is faster than Itachi and stronger in terms of physical strength, he wields sword with extreme mastery (flowing his elemental chakra through them), and now posses Samehada, his strength is superior to A's in his lightning armor v2 since he won him in a lariat contest. He can go in partial and full bijuu transformations and is able to block almost any jutsu with these transformations like he did against Kurama's TBB (Naruto vs Kurama) as well as use it offensively shooting TBB's without fully transforming. He is not as intelligent as Itachi, nor is he close, but his physical strength is far superior. Itachi's only chance would be a Complete Susano'o with the totsuka sword and yata mirror, using this means Itachi will suffer muscle strain pretty quickly, much before Bee has fatigued or come close to it. Bee can dodge the totsuka blade pretty easily due to his speed and can probably break the Susano'o with a multi TBB since this would mean the Yata mirror can't deflect all of them as its size doesn't fully secure the Susano'o, and the Susano'o would easily break from a TBB let alone multi-TBB
