An easy way to acquire ability in the Art is through devils (by being given the Black Flame directly through a contract or through consumption of devil flesh), since they are natural liars and have a tenuous hold on reality due to their chaotic nature. Doing so caused a small mark or deformity, known as a Devil’s Kiss, to appear on the body, a small tumour or part of the body which has been turned Devil, and can grow to consume the user. It was the Demiurges who first walked the Void and who dared to subdue, mask, and named devils to learn their secrets and bind them into service.[1] When Allison returns to the Void she meets three Magisters who are out making pacts with a devil and seeking to bind it with a new mask.[2]
Allison gets a Devil's Kiss[3]
Binding a Devil[2]
Magisters making a deal[2]