Kishi once said that he series will most likely end this year and we can feel that after the final battle of Naruto and Sasuke. What is the mysteries left in the series you want to know? Here are my lists:
1. How did Hashirama die?
2. With almost all of the justsu of Tobirama we saw in the series then how could Kinkaku and Ginkaku kill him?
3. How did Hamura die?
4. Is Hiruzen really stronger than Hashirama and Tobirama?
5. Why did Kaguya need the White Zetsu army while she already powerful? Are there any mysterious forces in the past?
6. The Uzumaki clan's origin?