"Young Bronze Boys! For the love and justice on earth, we are about to die and devote all our souls and lives..." Before the death of Golden Saint Shaka, he spent his last life talking to other Golden Saints to lead Bronze, and then fell asleep.
In this world, he has not yet woken up.
When he was reincarnated, unfortunately, his brother in this life returned to the world because of "unknown", where he learned a lot - what a capable person should learn.
Abe Seimei? Don't know the name. Shaka thought.
But even as powerful as he is, he will die again for various reasons.
He came to Soul Society.
There, Shaka finally learned his identity...