![sweat.gif](http://www.narusaku.com/style_emoticons/default/sweat.gif)
There are a lot of ways that this can go, but there are a lot of things that we have learned in part 2 that may help narrow it down.
What we know...
1. Sage Mode carries a lot of risks, without having someone with him to create a distraction or having clones standing by already infused with natural energy, then Naruto is vulnerable. Sage mode is also short lived, so against a tough opponent like Pain, the energy is depleted very quickly leaving Naruto, againn, vulnerable.
2. The 4th Hokage sealed the Nine Tails Chakra inside Naruto, to act as protection while he was young, and now that he is older, to use it to become even stronger
3. Only half of the fox's chakra is sealed within Naruto
4. A key exists that can unlock the seal and allow Naruto to access all the chakra within him, this is dangerous because Naruto has not yet learned how to control the fox
5. The 4th Hokage left behind a second unfinished jutsu, presumablely so that Naruto could one day complete it
6. The 4th Hokage faced Madara and was unable to defeat him
7. In order for Madara to achieve his ultimate power, he must extract the two remaining tailed beasts
8. Killer Bee knows how to contrl his tailed beast
9. Kakashi both posseses a space time ninjutsu and witnessed both the 4th Hokage's and Madara's space time ninjutsu with the Sharingan
10. Tsunade knew the 4th, is the grandaughter of the 1st that developed had the ability to contrl the tailed beasts, and has had access to all of the information cllected by her predecessors
So what can we take from all of this?
I have come up with three scenarios that are possibilities
But for my scenarios to be plausible I have made 2 assumptions
1. Sage Mode has served it's purpose and will not be focal point of Naruto's growth - We have only seen a brief moment where natural energy and nine tails chakra actually combine when Naruto confronted Nagato, so we know the two types of energy can be used simultaneously. However, I don't believe that natural energy and the nine tails chakra can mix effectively for battle, because natural energy requires too much focus, is too short lived, and requires the user to remain calm. The nine tails chakra is raw emotion that drastically alters Naruto's physical and mental state.
2. Madara is the final villain. All of the biggest troubles of Naruto's life stem from this one character.
-- He forced used the nine tails to attack the villiage, making the villiage despise Naruto during his childhood
-- He killed Naruto's father
-- He was using Pain to collect the tailed beasts, leading Akatsuki to nearly kill Gara, to kill Jiraya, and destroy his villiage
-- He is now manipulating Sauske to achieve his end goal
I believe Sauske will ultimately be redeemed (he may be used as a weapon, but I don't think he will be able kill Madara and take his place in achieving ultimate power)
Kabuto will make another appearance, but I don't think that he poses a serious threat, especially with the alliance formed to protect Naruto
Danzo will be involved with Kohona and it's role in the alliance, he may be Tsunade's final opponent in the end
These are only my thoughts and Kishimoto may go in a different direction entirely.
From all of this, I see three possibilities.
1. Most straightforward and uncomplicated
-- Bee teaches Naruto to control the nine tails chakra
-- Naruto takes it to another level and surpases Bee discovering a form that causes very little physical change aside from a drastic power increase (just as he surpased Jiraya with sage mode)
-- Naruto learns more about the 4th, the nine tails, and the sage of the six paths from Tsunade
-- the key is bestowed to Naruto so that he can take his powers to the extreme
-- Kakashi helps Naruto complete the jutsu left for him by the 4th, my guess is a space time ninjutsu that can help him defeat Madara, he can only complete the jutsu with the chakra of the ninetails, I don't think that an advanced sealing jutsu would require that much chakra
(the final three points here apply to all of my theories.
2. The yang chakra is extracted from Naruto by Madara, causing him to die temporarily. The solution, without anyone else sacrificing themselves, may be to find and seal the yin chakra within him. What if the yin chakra were different and allowed Naruto a higher degree of control than Bee has? Then Naruto would be able to complete his training and Madara would have a portion of the nine tail's chakra to revive the 10 tails, thus leading to the ultimate confrontation.
3. (LONG SHOT) The half of the ninetails chakra that was sealed within Naruto purposfully works against his own charkra making it stronger. If it were to be removed, Naruto's own chakra could be used to it's fullest extent. Bascially, the fox would be a chakra training weight. Whether the fox were removed by an ally to achieve this power or a foe allowing him to unintentionally achieve this power I don't know, but he would have superior control and stamina. The biggest problem with this theory is that no matter how much chakra Naruto has, it still probably won't be enough to confront the combined powers of the tailed beasts
Anyway, all just theories that I have had floating around in my head for awhile now. Some of these may happen, but then again they might not. I was just was curious if anyone else had any ideas that I may not have thought of.