Underworld is a Evil Spirit. It can create skeletons that belonged to the killed humans and spirit beasts that were killed by it.
Innate Domain Edit
This Spirit came with a Innate Domain called Underworld Death Domain.It appear as a gray fog. Twelve skeleton warriors also appear alongside it. They kill people and heir flesh and blood were devoured by his Underworld Death Domain and were converted into the user’s strength. They grew with him and became more powerful as he did. The twelve skeletons will evolve with the user and can be equipped with Battle Armors.
Initially, this domain could only encompass a range of a dozen meters.