Who is The Leader/Tamotsu Fukada from 1Q84 and what is their importance?

Former professor, Tamotsu Fukada, is a communist and the mysterious leader of the religious cult, Sakigake. He hears the voices of the Little People, who are strange beings that talk to him and force him to carry out their will. As a result, he suffers extended bouts of physical paralysis. Aware he is dying, Fukada wants nothing more than to be put pit of his misery. He cannot, however, find it within himself to take his own life. In the end, he explains his life to Aomame, and afterward, he convinces her to kill him.