Hello Tension, the Hell deities are the spiritual police force and justice system of Chinese folk religion. They deal with matters concerning death and the afterlife, are involved in the punishment of sinners, and are good at subduing evil spirits.
I worship them because they been very kind to me, protecting me from harm and guiding me throughout my life. My line of work involves regularly dealing with people who are either close to death or already dead - I used to work in a funeral home, and currently work as an emergency room doctor.
Hell-based chants and talismans are somewhat different from those associated with Heavenly deities. For instance, Hell talismans may contain dark or death-related images, such as skulls and bat's wings, and are often green in colour, instead of the usual yellow (see below).


Incense/joss sticks are normally offered to them in multiples of seven rather than the usual three. Seven is a number that is closely associated with the Hellish or Yin side - the moon, a Yin heavenly body, has seven phases; a newly departed soul can stay on earth for up to 49 days before leaving for the next world (49 is made up of seven sevens); and the Seventh Month is when the Hungry Ghost Festival takes place.
Also, Hell deities prefer 'rougher' offerings such as roasted meat, alcohol, opium and cigarettes (see below).

Check this out:  http://www.white-sun.com/journeys_to_the_underworld.htm]Journeys to the Underworld[/URL]

I am not sure how true is the story. Ji Gong was instructed by Jade Emperor to bring a medium to tour the hell.

As I've said earlier, I wouldn't put much trust in Yang Sheng's glorified novel.

Neither would I do so for Guai Tan, which is by and large a load of garbage.

Please re-read what I have posted previously about 'Hell tours'.