I Became the Heir to the Underworld

It is said that there has been a theory of "Yin and Yang Realm" in the world since ancient times. In ancient times, after the death of a living being, the spiritual light in the body should follow the laws of heaven, break away from the origin of things, return to heaven, and re-enter reincarnation. However, if you have a strong obsession when you die, this obsession will turn into something strange and contrary to the common sense of reincarnation. This type of existence has lost its past memory, acts only based on obsession, and devours living beings wantonly due to its instinct to survive and become stronger. People in the world are afraid and hiding, unable to compete, so they can only rely on sacrifices and offerings to protect themselves, and even regard these aliens as "gods". Later, the ancestors opened up the Netherworld to suppress and accommodate such aliens, and peace returned to the world. But if the underworld collapses, what will happen to the human world?