Charcoal Smoke is a move used by Sulfur Pot.
He aims both of his hands at his opponent and releases large amounts of gunpowder in the entire area. However, this move on it's own is not much of a threat until something that can ignite the gunpowder causing it to catch on fire, searing anything in the cloud of gunpowder.
Sulfur Pot usually has Nidhogg ignite it with it's own special move, Scorching Inferno. This move is extremely powerful as it was able to take down Crimson Kingbolt who is using his Mega Machine Awakening ability at the time.