Tobirama's death has already been revealed...Tobirama died when the Kinkaku-Ginkaku brothers of Kumogakure attacked Tobirama and his unit outside Konoha...they were greatly outnumbered....His unit had Danzo, Hiruzen, Kagari uchiha and the two current councillors of Konoha...the only way to escape was if someone became a decoy...When Tobirama asked this question,Hiruzen said he would be the decoy since he was the strongest within Tobirama's unit...immediately after that Danzo said he'll be the decoy instead of Hiruzen...After hearing both Hiruzen and Danzo,Tobirama decided that he himself would be the decoy for the others to escape....Then,Tobirama scolded Danzo for always competing with Hiruzen...and named Hiruzen as the next Hokage....All this was revealed when Danzo was dying...I want to see more of hiruzen and minato, also madara's thrump card and rikudous backstory. And i want to know how the hell hashirama and tobirama died.