Black Flame (黒炎 koku en) is an Extra Skill that allows the user to release very destructive Black Flames from their body. The technique uses one's internal magic, and the maximum size of a flame may reflect on their user's power.
By creating a field of magic, transforming it into flames, and then launching it away, fire can be created from thin air. The temperature of the flames can be adjusted based on how much magic is used.
Rimuru acquired this Skill when he fused the Extra Skills Water Manipulation, Fire Manipulation, and Combustion via Unique Skill Deviant, resulting in the acquisition of Black Flame and Molecular Manipulation.
- In Veldora's Journal, Veldora mentions that Black Flames are "his flames," though probably in a way that's different from the specific Extra Skill Black Flame.