Flames that do not extinguish naturally and, if left uncontrolled, burn more and more fiercely. When people burdened with sin are scorched by Karman, they endure pain far beyond that of ordinary flames — pain that is unbearable.
Karman does not belong to Four Elements. As the name suggests, Karman is a kind of cause and effect.
In fact, ordinary fire burns by consuming oxygen, while the Karman burns by consuming precisely the sin of whatever it ignites.