Races like humans, elves, dwarves, halflings and gnomes who get corrupted by Ghor are often referred to as Warlocks or Necromancers. Both of them are twisted versions of whatever race they used to be. It is said that the more a warlock or a necromancer gives in to the corruption, the more powers they get and the more twisted their appearance will be. It is believed that one does not become a warlock when Ghor whispers in his or her ears, but only when they listen and start to use whatever powers Ghor has given them. But using this corrupted form of magic further corrupts the wielder and thus Warlocks and Necromancers by definition are chaotic and evil.
The difference between a warlock and a necromancers is that warlocks mostly use their powers to spread corruption and plagues while necromancers tend to have an obsession with death. A powerful enough necromancer can create undead and force their will upon the lifeless beings, a warlock cannot.