your the son of Pain and Konan(you have the rinnegan). And your a Akatsuki member. You're the same age as Naruto (in the Shippuden timeline). You're also itachi student and your partner is zetsu. You were on a mission with zetsu when you opened the scroll you got teleported to the past where Naruto was a kid and the first chunin Exam was going on along with jiraya training Naruto. You walked through the hidden leaf wearing a disguise trying to keep a low profile. As you did. You saw kisame and Itachi facing off against asuma and kurenai. (This was before you joined the Akatsuki and before you met itachi so they didn't know you yet).

Asuma: you got some nerve coming back here.

Kisame: these friends of yours. itachi?

Kurenai: you're the s rank rogue ninja. Kisame Hoshigaki. Time skip to where they started fighting and soon overpowered. Kurenai was fighting Itachi on the water while kisame was about to use water style shark bomb on asuma but you used the same Jutsu cannceling each other out. (I know it's kakashi but for this. It's you doing it instead). You cancelled your self in a genjutsu to make yourself invisible as Itachi used his shirigan to see through it while everyone else couldn't see you