Who is Kenzo Isozaki from The Rise of Endymion and what is their importance?

Kenzo Isozaki is described as a cunning man with indomitable will. He is the leader of the largest trading firm in the Pax, and he will eventually become a Knight of the Cross. Kenzo will lead the attack against an Ouster Startree, before turning on the Church following the shared moments of Aenea's martyrdom.