(Tsunade was not Princess Kaguya's reincarnation. Tsunade was included to introduce the later storyline involving the Sannin. Princess Kaguya was simply Princess Kaguya.)
Three months after Madara Uchiha gave his Rinnegan to Izuna,
Izuna had already transplanted the Rinnegan and adjusted to them.
As Madara's younger brother, Izuna knew his brother's personality better than anyone.
Once he made a decision, he never changed it lightly.
And so, Izuna could only accept the Rinnegan through his tears.
Because of this, he embarked on a path of revenge against Konoha.
There was already the old blood debt he held against Tobirama Senju.
Then, through Tobirama Senju's maneuvering,
the Uchiha's power had been steadily curtailed.
With old grudges piled atop new ones, Izuna immediately wanted revenge on Tobirama Senju.
At last, he seized an opportunity to assassinate Tobirama while he was out alone.
But Tobirama Senju used Flying Thunder God to hold out for a long time.
In the end, however, he was no match for Izuna with his Rinnegan.
"You owe me a life. Now I've come to collect."
Wearing his new "colored contacts," Izuna spoke coolly to the dying Tobirama.
By then, the battle had already drawn the attention of Konoha's other ninja, and Hashirama Senju finally arrived after hearing the news.
Seeing Tobirama Senju dead, he flew into a rage.
He clashed with Uchiha Izuna.
Both of them fought with genuine fury.
Uchiha Izuna had long resented the Senju Clan's actions,
while Hashirama Senju had just lost his younger brother.
The battle finally ended with Izuna retreating in defeat.
Hashirama Senju was still Hashirama Senju, after all. His chakra reserves far surpassed anything Izuna could match.
And Izuna had only recently transplanted the Rinnegan; he had yet to master them completely.
But the Rinnegan were terrifying nonetheless, and Hashirama suffered