Who is Omar from Mao II and what is their importance?

Street person Omar becomes a kind of guide for Karen once she leaves Bill's house and submerges herself in the street life of New York City. He protects her with both advice and with action, and becomes an ally in her quest to give people living the street life a little something better. In short, he helps her realize the little personal ambition and/or drive she has the capacity to act on.