Why is Kisame so powerful?
He can fight Gai with the 7th gate open, can fight a four-tailed beast solo without much injury.
He has chakra reserves that can compare with the tailed beasts themselves.
Does this ring a bell?
Yes, Senju or Uzumaki. Basically the younger son of the Rikudou sage.
Even in the Senju or Uzumaki, pure as they are of the Senju ancestor blood, chakra reserves like that are rare to come by. Odds are very low that someone totally unrelated could come up with such power naturally.
In any case, it's been centuries since the Rikudou last lived. This blood shouldn't be very exclusive now. It should have pretty much spread out.
Is he genetically related (naturally by inheritance or artificially by science) to this particular bloodline?
Does this have anything to do with his looks?
We do know for certain that some senju (specifically the first and second hokage) have water nature alignment. This theory shouldn't be too far off.
Neji compared 30% of Kisame's chakra to Naruto.
There's also a Page where Pain states Kisame has the largest Chakra Pool in all of Akatsuki, but that may have been a mistranslation, since the new versions of those translations word it a little differently.
Imho Kisame is either something like a Shark Sage (which would explain the appearance and the monstrous strength) or his body was modified by Kirigakure scientists... or he's just a member of an unknown clan which simply happens to have such brutish physiques.
However, I don't think Kisame has any affiliation to the Senju, Uzumaki or even the Rikudou's sons.
I disagree, imho Kisame is a natural tank, no experiment nor sage or whatever, he was a genuine monster.
I really hope, for one, that he is not related to Rikudou, hell I really don't want for any peculiar ability to be linked to Rikudou, since it would mean that only those with something of Rikudou inside them are destined to something great.
Personally I believe Kisame was someone who trained a lot, had a lot of talent and natural stamina, hell the Fourth Raikage has chakra compared to a Bijuu and hasn't any correlation to the Sage.
I believe Kisame to be the same, a guy born naturally gifted that exploited his talents to the limit. He is basically a Naruto on steroids
in the volume edition,that is the most complete one,pain said he was the member with the greatest amount of chakra. the fact he had more chakra than nagato(an uzumaki) says a lot of things. btw,I'm 100%sure that he is not neither uzumaki nor senju related.
Well, a great deal of kisame's strength and stamina was directly connected to his samehada. The only reason he was able to fight be in any of his biju forms was due to that IMO. I mean, bee did land a killing blow on kisame and it was his sword that saved him. I do think he is a natural tank to the very extreme of the word and I doubt he had relation to the senju (no such thing has been ever said or implied). Having a lot of chakra does not automatically make someone a senju IMO.