Devil

Devils, not to be confused with Demons are the fallen, cursed servants of a deity they once betrayed and killed. Devils are mainly interested in gathering mortal souls, not in rampant destruction and chaos. Though they plot and scheme amongst each other, they ultimately work together for the greater goal of soul-gathering in the Nine Hells. Devils never renege on a deal, but tend to deliver exactly what is asked for.

Infernal Pact Warlocks gain their power from pacts with devils, ultimately giving up their souls for it. Very few people have ever gotten out of paying that final price.