Fire

Fire is a chemical reaction caused by combustion due to extreme heat. It is also a powerful and versatile implement against, by or with the supernatural.

Uses
Fire is used in many procedures, rituals and spells. The following are the common uses of fire in the supernatural world.

Against Ghosts
Fire, in conjunction with salt, is a known permanent deterrent for ghosts and similar beings when used on their bodily remains or earthly possessions.

Against Demons
Although normally resistant to conventional fire, demons could still be harmed depending on the use and intensity of fire. They are vulnerable to fire when their skeletal remains are exposed to it. This was considered to be a myth, until Bobby tried it successfully on a Crossroad Demon. Much like how a ghost or a vengeful spirit does, the demon burns and permanently ceases to exist. Unfortunately, their vessel burns to ashes as a result. This is also an effective means of torture as partially scorching a demon's bones hurts them. However, it requires knowing the demon's true name and the location of their bones and many demons due to centuries of torture have forgotten their original names or that they were once human at all.

Against Monsters
Fire is also fatal to many creatures such as wendigos, changelings and rugarus. In most cases, fire is also the only weapon that will work against such creatures. Thus, many hunters weaponize fire by using flare guns, flamethrowers and blowtorches.

Holy Fire
Fire could be also used with Holy Oil to create Holy Fire. This is used against beings of angelic origin. It is rather versatile, as it could deter or even fatally harm angels, and it could temporarily banish powerful archangels.

Used in forming rings of holy oil, it could prevent angels from escaping. However, they could still access their powers and break free if they are resourceful and creative enough to create a gap within the flames. Holy flames could be used to create a molotov cocktail as an offensive weapon. Although primarily used against angels, Holy Fire could still hurt demons as shown when Sam drenches Abaddon in it and sets her on fire and when Castiel tosses Meg onto a ring of Holy Fire to escape it. However, unlike with angels, it is incapable of killing demons.

Another use for Holy Fire is if an object is scorched with it, such as glasses, it allows a person looking through that object to see the normally invisible Hellhounds.

Rituals


Fire is also used by psychics in different rituals such as séances or by witches in performing their spells, such as a tracking spell. Many summoning rituals require not just a candle, but a lit matchstick thrown into a bowl of mixed magical ingredients as the final step. This is seen on rituals summoning demons like Azazel, or on rituals summoning angels, as seen when Balthazar was summoned by Sam Winchester.

Conjuration
Certain supernatural beings are also able to magically conjure and command fire, regardless of their alignment. Azazel of hell, Kali of the pagan deities, the phoenix of monsters and Michael of heaven are prime examples. This ability is called pyrokinesis.