Crossing to the Naruto World, Uchiha Tonan obtained the ‘Legacy Inheritance System’. As long as the people who acknowledged him died, he could inherit all abilities of the deceased.
Therefore…
“Konoha’s higher-ups mistreated the Uchihas. So, I’ve decided to lead the clan to launch a coup d’état after three years.”
“Ding! Gained Uchiha clan’s acknowledgment.”
Two years later.
“Tonan, this is the evidence of the Uchiha clan’s betrayal. When all is said and done, it’s your clan. So, I want to hear your opinion.”
“I’ll always stand on the village’s side.”
On that fateful night, Tonan stood on the Hokage Rock, coldly watching the Uchihas’ annihilation.
He spread his hands, being grateful to his clansmen’s gifts.
The next day.
“Lord Hokage, I shed blood for Konoha and became the village’s sword. And this was how you treated the meritorious clan.”
“Tonan, didn’t you agree to it!?”
“I don’t know what you are talking about. The fury of clan extermination is irreconcilable. Today, I will destroy the Sarutobi and Shimura clans to appease my clan members’ souls in heaven.”
A high-leveled hunter often puts on a disguise to lower the prey’s guard.
Chapter 39: BLOOD... IT’S MY BLOOD!
Chapter 264: Kikyo War, Who’s Behind the Scenes
Chapter 278 
Chapter 632: The Way of Heaven Is Strong (The Finale)