A profession that has existed since people learned how to actually use Essence Cores in the Age of Construction which ramped up the demand for them. The first Core hunters appeared and they were numerous because, for many, it was a quick way to make some money. This led to Essence Beings hunted almost everywhere and Cores being sold to various people that used them for different reasons, like researchers that were inventing Essence Weapons.
All of this hunting everywhere, however, led to a massive number of Essence Beings dying. So many, it actually seemed like it had an effect on the Essence Energy surrounding the Horhsalians. Essence researchers were worried that continuing this hunting craze could hurt it even more. Countries started to establish new laws that forbad the hunting of Essence Beings except through official hunters hired by the state.
The people reacted quickly and a possible crisis was averted. The amount of Essence Beings recovered over the centuries and the laws were lifted a long time later, especially because of the occurrence of Solid Essence which made Essence Cores redundant in some areas, like energy consumption.
Core hunters, as should be obvious, hunt Essence Beings to get their Essence Cores but there are also those that hunt Essence Beings that have become dangerous, like tainted ones. Their reasons for doing this vary from person to person. Some of them keep the Cores for themselves and like to use them or save them for later while most others sell them. Core hunters are popular with countries, companies, and Unions that like to get even more Essence Cores but want to task someone else with it. They are also popular with Catalyzers although Aggressors, Farslingers, and Supplicants can make use of Essence Cores as well. Of course, most adventurers try to get more Cores themselves but there are some that do not like/want to fight Essence Beings or they live in an area where there are still laws forbidding people to hunt them.
Core hunters are combatants since Essence Beings usually do not fall into traps and for tricks that would work on a regular creature. They like to categorize themselves depending on their experience and add the prefix of the strongest Essence Being they can hunt, like Young Core hunter even if they are older but only can hunt Young Essence Beings (which would be kind of embarrassing). As you can guess, Ancient Core hunters are rare and legendary ones do not exist - people that are able to kill a Legendary Essence Being would probably do something else than just being a regular Core hunter. All of them are specialized to fight Essence Beings which is why Repudiators are extremely popular within their hunting groups and they are usually the ones to get contracts first.
Everyone can become a Core hunter but they still have to regulate their hunts since people do not want to repeat what happened in the past by killing too many Essence Beings. There are some Core hunter guilds here and there but there is no big international group or Union backing them, so most Core hunters either belong to a specific hunting group, a guild or work alone. Some like to stick to one area they are familiar with while others travel around. Each one of them is different and there is no mutual goal uniting them.
Edited by Gota