Hello. About shinobi. In the Japanese magazine before release of DOA5LR, there was a brief look on Raidou's biography, and it was stated that Raidou is also "Nukenin" (抜け忍, Runaway shinobi) just like Kasumi. I read about this somewhere too. And about article Exiled shinobi: I found out that the termin "Bōmeinin" (亡命忍) is not exist in Japan and in Ninja History as well as in DOA series. Please correct this mistakes since I'm bad at grammar. Thanks in advance.
This is quite complicated, yes Raidou left after Shiden was chosen as clan's leader, but Raidou returns and raped Ayame, being enraged by this, Shiden completely break all ties with his older brother and send him away.