Who is Repairman Jack from Legacies and what is their importance?

Repairman Jack lives in New York City, where he provides a service to help people who need justice but cannot get it through normal channels. Because of this, Jack lives off the grid, without a social security number or any other identification that someone might use to track him. Jack assists several people, including a man who runs a janitorial service. He also runs a scam on an unscrupulous business man in order to get back money his client is owed for services performed. Jack is in love with Gia.