Naruto: I am Shisui

Uchiha Shisui is a prodigy, a loyal shinobi, and exactly four weeks away from jumping off a cliff to prevent a civil war. Or, he was, until he inherited the memories of a boy from another universe and realized his world's future is public knowledge. Forewarned of his coming end and the dark fate awaiting his best friend, Itachi, Shisui rejects Such destiny.