They have a few variation on their title. Demons of the Black Flame: Lords of the Black Flame, Masters of the Black Flame, Lords of the Black Sun, essentially a type of demon who specializes in working with the Black Flame. They area a type of demons is a demon that has embarked on a transformative journey through the depth of the void to attain mastery over themselves and the Black Flame.
I first became aware of the Black Flame many years ago. It is found from deep in the Void. Now one thing about the Void. The void is a realm close to the Abyssal Realm but it is much darker and way more sinister. The Void is of Darkness, Blackness and when we peer into the void, it changes us, we are watched, and we watch, there are creatures in there that do not sleep, they lie in wait, waiting, waiting for prey.
It is full of illusion and confusion, brining you face to face with your fears and horrors, your secret desires and sides of yourself you deny. You become the monster you hate, you can lose yourself completely to the issulsion and temptations. It is seductive, insidious, yet you only want to run away, but cannot. It offers you what you want, strips you bare then leaves you with what you fear. It is a journey in itself that can lead to destruction and madness.
Void Demons do exist, they reside in the void. They are dark and sinister, hollow in form and appearance and look like they will suck the soul right out of you and they will. They are what they are. Hollow black eyes and hallow black mouths they slither and slide along and move in unsettling movements that chill the soul to the bone. They also can take familiar forms, changing and offering up intense illusions to confuse us and lead us astray.
The Demons of the Black Flame (on the other hand) are not demon from the void, they are Demons who have embarked on a perilous and dangerous journey into the void to master themselves and the Black Flame. They have a set journey they must undertake, accomplishment they must meet, and their mental training and discipline but be at the level where they will not slip and fall, getting lost forever in the void to be torn to shreds.
On their journey, if successful, they will be transformed and enhanced by the power of the Black Flame. Their experiences in the void changes them and allows them access to great power and ability, they also gain incredible control over the Black Flame. Controlling the black flame, they are changed forever as the energies of the void and the black flame are fused with their own being. As they learn to control the flame and their new abilities their natural talents merge and they start to develop their own foundation with the black flame.
The Black Flame, it is from the void, it is healing and destructive, transformative, dangerous, empowering, corrupting, incinerating. It is a weapon, a defensive shield, a living flame, a flame of death. It changes you, destroys barriers, breaks down your defences, heals your soul, put you in touch with the deepest dark nest sides of yourself and gives you freedom. It is all these things and the individual demons who work with it, they learn about it and they learn their place with working with the black flame, and as they journey, discovering more and more, they attain mastery.
The Demon who work with it, have gone through perils and darkness to master it, and their skill with it is incredible and unique to each individual Demon. They all have one thing in common though, they have attained mastery, and in that mastery they have become, the Demons of the Black Flame.