Devil_Hex
I think Fujin should request Hiruzen to teach him the normal Rasengan so that he can show the Wind-Rasengan, Rasenshuriken & Rasengan-Cannon as the improvements done by him, proving himself to be a kind of Ninjutsu-Genius. At the same time, Fujjin should meet & be-friend Kakashi to learn Chidori & then secretly improve upon it to develop Purple-Lightning (Shiden) Jutsu.