The Warlock has sold their soul for power. The Warlock is a spellcaster, with an odd assortment of debilitating and devastating spells, eldritch blasts, and heavy, sometimes traitorous obligations to an unknowable, extremely powerful entity. The Warlock’s major feature besides is their Patron, a GM character created between the player and the GM, who can be as present a force in the game as you wish (or fear).