My grandfather passed away mysteriously when he was 36 years old. He accidentally got Yin Yang eyes. Later he learned Maoshan Feng Shui and then got the merit exchange system. As long as you kill an evil ghost or save a ghost, you will get merit points, which can be exchanged for magic weapons in the underworld.
Life has never been the same since. He shuttled between the Yin and Yang realms, helping those souls who could not be reincarnated to be liberated, and also engaged in fierce battles with evil ghosts.
Later, he fought against the Great Demon King of the Underworld, and after rectifying the underworld, he became the messenger of Yin and Yang.
Still think it's pretty good.