Zetsu/Sakura and 'Terrarium'
Sakura gets trapped in the time stream and basically ends up being bounced from place to place. Everywhere she goes is tied to the history of Konoha and she begins to piece it all together. Unfortunately, her exploration of time isn’t anywhere near linear. The only thing that ever remains the same is…well…
He’s always there, some way or another.
As Sakura finds out the truth, how Zetsu is responsible for so many deaths, she decides to change it.
She befriends him.
It takes some doing and some failed attempts (Indra and Ashura) before she manages to overcome his tie to Kaguya. There is still the pesky side-effect of her jumping through time and ending up in so many branching, shattering time streams.
The only thing that keeps her sane is Zetsu.
He begins to work to stop the time travel, knowing the toll it wreaks upon her. He’s come to care for her.
She’s his first friend.
His only friend.
It isn’t meant to be.
Suddenly, she just…stops appearing.
Zetsu is alone.