Humans
Human folk of the life realms.
Humans are pure souls- not yet touched by Heaven or Hell spirits. When they die, the go to purgatory and enter the reincarnation process to become a new creature born to a life realm. However, if they are pulled into Heaven or Hell by a Torture Demon or Purifier Angel, they are warped into the final stage of their soul life- Demon or Angel.
Humans that hunt demons (not to kill). They capture demons and imprison them for their wrong doings in the land.
Demon Slayers kill demons. They seek them out and destroy them regardless of what they have done in the land. Their existence in the life realms is crime enough.
Demon Tamers are a little like mercenaries. They are hired (usually) by Demon Hunters to tame dangerous captured demons in the Hunter kingdom. Turning demons into pets or ensuring they submit to humans commands when needed.