Vulcain is Asmodehus' main and most trusted servant. We do not know much about him and his origins but he is very loyal and devoted to the lord of fire.
Vulcain is similar to Asmodehus in appearance but differs in being made entirely of fire.
Vulcain's power is very similar to Attila's.
He is entirely composed of fire so most physical attacks are rendered useless.
Being made of fire, we are led to believed his battle potential is extremely high.
Although He used to be between Neil And Charly in volume 5 it seems he has since improved.
Vulcan is known to be the Firelords right hand man he is completely composed of fire. He in term of strength is between Charly and Neil in Volume 5. He fought Raiden in Volume 10.