You need a specific building to create undead.In order to create undead and corrupt living, you need to first get corruption and spend corruption to corrupt the living.Trying to cast while starving, low health, wearing armor, etc will increase the change of failure.if the player fails to cast the spell, the flames will not disappear, will hit the caster.Moving or being hit increases the chance of failing.The player need to learn the spell from a demon, by bargaining with a demon or enslaving a demon.How the Fires of Gehenna should work on Conan Exiles? Honestly, i think that demonology should be the more risk than on AoC, for example. There are skeletons on the game, but the player can’t create or command skeletons The developers made a really good work with magic on AoC, but on Conan Exiles, while players can summon a deity’s Avatar who is eqquivalent to a epic level divine magic in D&D, players can’t do anything similar to low tier arcane magic. By this reason, sorcerers are or persecuted like on Aquilonian society or rulers, like White hand rules Hyperborean.
Magic on Conan universe is powerful, but is not power without risk or consequence. Honestly, i play mostly as mage in games cuz i wanna do things that i can’t do in real life and i can pratice with swords in real life.