Warlocks are known for creating Pacts with creatures of the Feywilds, Outer Planes, and even Infernal pacts. Though in Dark Sun the most common Pact is that of the Sorcerer-King. Sorcerer-King Pact warlocks do not have to be Templars.
Sorcerer-Kings do not just need loyal Templars, but they also need to train others in the ways of magic. Sanctioned warlocks are known to exist in some city-states. Most are spies for the Sorcerer-King, others are adept magic users that the Sorcerer-King saw potential in.
A pact made with a Sorcerer-King is permanent for all extensive purposes and can only be undone by the Sorcerer-King himself. Those that trick the Sorcerer-King into granting them magical abilities sometimes leave the city to find ancient secrets for their master or escape their master's sight to carry on with their own agendas.