Naruto: Uchiha, Fused with Tobirama at the Start

Eiji transmigrates into the world of Naruto and becomes an ordinary member of the Uchiha clan.

With the night of the clan's massacre only three years away, Eiji has quite a headache on his hands.

At the critical moment, he successfully activates a system:

Strongest Template System activated.

Senju Tobirama Template bound.

From this day forward, I'm the man who made a pact with the sea!

The Flying Thunder God Technique, mastery of forbidden jutsu, ninja-world science, and even senjutsu-he's taking them all!

From then on, Eiji bears the Uchiha name, yet becomes the spitting image of the Second Hokage.

Lord Tobirama's Sharingan-which he acquired from who knows where-has successfully evolved into the Mangekyo Sharingan!

Lord Tobirama has quelled the rebellion at minimal cost. Just what we'd expect from you!

Wait, Lord Tobirama has become the Uchiha clan head?

Until one day, the light of the Impure World Reincarnation shines...

Senju Tobirama stares at this white-haired, red-eyed Uchiha brat, who finds all sorts of ingenious ways to use forbidden jutsu, and is utterly dumbfounded.

"Why is this inherently evil Uchiha brat exactly like me when I was young?!"