Who was Kuan-Ti?
Like Cheng-Huang, Kuan-Ti was a god based on a real man. According to the story, he was born poor and when he was a child he sold tofu for a living on the street (but historians say tofu was not actually invented until the Song Dynasty, hundreds of years later).
He was a famous general during the Han Dynasty (about 200 BC-200 AD). Kuan-Ti is always shown as a red-faced man dressed in green. He was a war god, who also protected people from evil demons, and from anything that was unfair. He's different from other war gods like the Greek god Ares because Kuan-Ti never starts wars, he only defends you when someone attacks you. He also could tell you the future.
Bibliography and further reading about Chinese gods:
The Gods and Goddesses of Ancient China, by Leonard Everett Fisher (2003). . One page for each god, with lots of pictures and some historical context.
Five Heavenly Emperors: Chinese Myths of Creation, by Song Nan Zhang (1994). Stories .
Chinese Mythology A to Z, by Jeremy Roberts (2004).
Dragons and Demons : Myths of China, by Stewart Ross (1998). A few Chinese stories, retold .
Dragons, Gods and Spirits from Chinese Mythology, by Tao Sanders (1983). More of a child's encyclopedia.