As the eighth head of Black Dragon, Izana Kurokawa had been vulnerable to treachery due to his isolation. In response, he founded Tenjiku and governed with an iron fist, all the while being influenced by one of his underlings.
Izana died by Kisaki's gun protecting his childhood friend Kakucho. Izana then proceeded to explain that he is not blood related to the Sanos at all—he was a child of Karen Kurokawa's ex-husband, who had Izana with a Filipino woman. He finally accepts that he isn't alone because of Kakucho, and accepts the defeat in his dying moments.
He had the possibility of being the kind, compassionate elder brother to Emma, but due to his years away, became ruthless and cruel. Not only has he become mentally unstable but, he strives for absolute power due to being helpless as a child.
Izana died by Kisakis gun protecting his childhood friend Kakucho. Izana then proceeded to explain that he is not blood related to the Sanos at all -
Due to his complex family history, Izana thought he was related to Shinichiro, Manjiro, and Emma. He loved and looked up to Shinichiro, and often sent him letters. Izana is jealous of his "younger half-brother" Manjiro because Shinichiro decided to pass on the Black Dragons to Manjiro, instead of Izana. After Shin died, there was nobody to help Izana stay on the right path.
By his orders, Tetta Kisaki murdered his sister Emma.