Kisame vs Naruto and Itachi vs Sasuke
Both Sasuke and Itachi used the fireball jutsu simultaneously, both of the jutsu collided with Sasuke having a slight advantage. As soon as Sasuke was about to win the collision he saw a black flame engulf everything, including his fire jutsu! "Amaterasu!"
The black flames burned all of Sasuke's flames before disappearing as if it was never there. Sasuke unconsciously took a step back, he was afraid of the flames. 'Naruto told me about those black flames, but I never thought they would be this powerful!'
Sasuke realized that he could just wait for the flames to come again, Sasuke ran around Itachi dodging the flames that were chasing him. Sasuke suddenly planted his foot and charged at Itachi full speed using his wings to speed him up. Itachi's eye closed due to pain and the black flames stopped.
"Fire style, Dragon barrage jutsu!" multiple fire dragon heads spewed out at Itachi who jumped up to dodge. Itachi was seriously injured and was hit by a few of the fire dragons. Sasuke charged up a Chidori and ran at Itachi full throttle, 'That Amaterasu earlier seems to have taken a toll on him. This is my chance!'
Sasuke extended the Chidori at Itachi, Itachi somehow pulled out enough chakra to use Amaterasu to burn even the lightning itself. Sasuke quickly detached from the lightning so he wouldn't get burned. 'Itachi doesn't have much chakra left, but neither do I, the curse mark takes a lot out of me.'
Sasuke fell to his knees as his curse mark went away, at that same time Itachi also fell to his knees holding his eye in pain. "This will probably be my last jutsu. This will be what will end you Itachi!"
(Naruto vs Kisame)
Naruto used his chakra arms and tails to lure him around the battlefield. Kisame continued to absorb Naruto chakra, Samehada liked the way the chakra tasted. "Take your own chakra back! Water Style, Super Water Shark Bomb Jutsu!" Kisame created a gigantic shark out of water and, by thrusting both hands forward, sent it to attack Naruto. This jutsu was able to absorb the chakra from Naruto's previous attacks and use that chakra to grow larger and more powerful. The powerful jutsu exploded right on Naruto creating an explosion that leveled the whole area!
'This chakra volume and quality is like nothing I have ever tasted!' Naruto pointed his arm at Kisame, the chakra around his arm started to take a strange shape, it almost looked like a fox head. The head spits out a ball of heavily condensed chakra. The head then let the chakra ball fall into its mouth eating it. Steam came out of its mouth.
"Let's go fox! Nine-tails chakra cannon!" The dark red chakra blast flew at Kisame with extreme speeds, 'there is no way I can absorb this much chakra!' The chakra blast collided with Kisame's body and sent him flying and crashing through almost a whole forest!
Kisame was leaning up against a tree and laughing, "The stronger my opponent, the stronger I become." the end of Samehada went up his sleeve and started to heal him, he was regenerating almost instantly. "I do not tire, I do not fall, I am much stronger than you are," Kisame said as he balanced himself.
[So his blade steals his enemy's chakra and transfers it to its master in the form of stamina.] said a deep voice inside of Naruto's head. "I am called the tailless tailed beast for a reason. Water style, super exploding water shock wave!" a giant bubble trapped everything in a giant bubble of water not letting anything escape!
"The longer this battle drags on, the more chakra I will take from you and the greater you will weaken. And I will grow proportionally stronger." Naruto couldn't breathe and had no footing to stand on. 'Fox, this is a problem!' [Yeah I know, if I put the rest of my chakra available to your face you should be able to breathe. But that means you will have to fight him without my chakra.]
Naruto nodded, 'That's ok, I can use sage mode to fight.' [Naruto, you have to take his sword away. The sword is the key to his strength.] "Yeah I got it, I'll take his sword!" as the foxes chakra went to his face Kisame started laughing. "You can take it, that's if you can pull it off my body!"
Samehada was absorbed by Kisame and he started transforming into a shark-like creature, well at least more shark-like than before. 'He merged with his sword?' [he's like a fish that became a man.] 'is he half fish half man. Or is he half man half fish?' [Stop thinking about stupid things he's coming!]
Naruto saw Kisame swimming at him at high speeds. Naruto wasted no time entering sage mode, Kisame and Naruto both clashed hands, they were nearly equal in strength. [Naruto, we should escape this water, he has the advantage!] Naruto pushed off Kisame and swam with his full speed.
"You cannot escape this water jutsu! I have the advantage!" Kisame quickly caught up with Naruto, [Naruto behind you!] Naruo managed to get out of the way at the last second dodging the attack. The fox inside Naruto began to notice that they couldn't escape, [Naruto the water is moving, I think it's moving with the fish guy. His speed is superior here we can't escape, we have to fight head-on!]
Naruto quickly turned around, he created a Rasenshuriken and threw it at Kisame. The water slowed down the jutsu enough to where Kisame could dodge it with his enhanced speed. 'Damn it, if I have a chance at beating that regeneration I'm going to need to hit my Rasenshuriken!' [We need to focus on landing any jutsu at the moment, don't lose concentration!]
[Because he is a fish he can breathe underwater, just running is going to get us killed eventually.] 'So what do we do?' [We have to slow him down and escape this water, the best way to do that is to make him heal himself, he shouldn't be able to move while doing that.] Naruto blocked the incoming attack from Kisame and retaliated with multiple blows trying to slow him down. Kisame absorbed his chakra each time Naruto attacked him!
Naruto noticed his natural energy coming out of him each blow so he backed up to make sure he didn't lose sage mode. Unexpectedly Kisame did not chase after him. Naruto looked at him and noticed something, his arm was half stone!
"I see, senjutsu chakra can be very hard to control, it looks like you are turning to stone." [Naruto, this is our chance, turn him to stone and we win!] "Yeah but he absorbed my chakra pretty fast, even with 3 clones I don't know how long I can last." [so I guess we'll just have to see who can last longer.] "My thoughts exactly! Hey fish, let's get started!"
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End of this chapter, Kurama is very smart so I don't think it's too hard to imagine him thinking of this.
Also, I have a good question, I was looking back at some of this earlier and began to wonder if Pre timeskip or Post timeskip was better. So let me know, Pre TS or Post TS for this fanfic?