Smelter Demon

Smelter Demon is an optional boss in Dark Souls II.

Location

 * The Smelter Demon is found on the right side of the open area in the Iron Keep, past the first two rooms with Alonne Knights.
 * A second Smelter Demon, which has a blue aura and glow, with horns raised upwards, is encountered at the end of the Iron Pathway, in the Crown of the Old Iron King DLC. It's different from the one fought in the Iron Keep, as the Blue Smelter Demon has raised horns on its head and lacks the horn on the right pauldron.It's also magic-based as opposed to the first Smelter Demon, which is fire-based.

Description
The Smelter Demon is similar to the Iron Golem in Dark Souls in that it is a construct made of Iron that is given life through some means. Its body is made entirely of Iron except for a portion of his chest, which is hollow and exposes a core of flames.

The Smelter Demon was responsible for the fall of the Iron Kingdom and the death of its ruler, the Iron King.

Strategy

 * 1) High fire resistance is recommended for this boss fight as the Smelter Demon will intensify the fire in its torso which will continuously damage the player if he/she is too close. After receiving more damage he will put his sword in his flaming "belly" and the sword will catch fire, making his attacks deal fire damage.
 * 2) Being a ranged character will greatly reduce the difficulty of this boss fight as most of his attacks can be easily dodged and the boss itself isn't too fast, allowing the player to do a great amount of damage.
 * 3) Summoning Lucatiel and letting her tank the boss is a great strategy for both ranged and melee characters, but she won't last long as her shield doesn't have 100% physical reduction and she doesn't defend very often. However, she will likely survive until the boss puts his sword in his "belly".
 * 4) A Gyrm Greatshield will enable the player to negate the fire damage once the Smelter Demon ignites his sword, drastically decreasing the difficulty of the fight.
 * 5) Using a Lifegem will mitigate the damage inflicted by being close to the Smelter Demon when he strengthens the flame in his torso.
 * 6) The Smelter Demon can execute a damaging AoE attack a few seconds after he lands from his jumping attack which can catch players off-guard.

If the player is using spells/miracles/hexes the fight will be easier as he doesn't need to deal with the fire damage inflicted by staying close to the Smelter Demon. If the player casts offensive miracles to the Smelter Demon, he should cast it once because of the delayed casting time of the spell; if the player attempts to cast another one, the Smelter Demon would probably connect a hit. Depending on the spells the player is using he can connect two hits (Great Heavy Soul Arrow) or one (Soul Vortex) depending on the cast time delay the spell has.

When the Smelter Demon is using his belly to power up himself, the player should avoid casting any type of magic because his defense rises when he does that, but the player should cast Dark Fog or Toxic Mist because the Smelter Demon isn't resistant to poison.

The player should avoid blocking the Smelter Demon attacks if he doesn't have high fire resistance, especially if the enemy imbues his weapon with fire damage, it's better to dodge his attacks because they're predictable.

Summoning

 * Lucatiel of Mirrah can be summoned for this fight.

Attacks
Overhead Slam: Holds his weapon with both hands and performs an overhead slam. If in the phase while the demon's sword is on fire, then it will shoot out a trail of flames.

Lunge: Charges at the player and thrusts his sword towards the player

Double Strike: Swings his sword twice in a row, sometimes follows it up with a jumping attack.

Jumping attack: Leaps towards the player and plunges his sword in the ground for a while. May decided to do an AoE explosion attack or simply take the sword out of the ground.

Flame Aura: After some health has been taken off the demon, will start an animation and buff himself up. This buff gives a flame aura that does damage while the player is really close to the demon.

Fire Blade: Stabs his belly with his sword and imbues it with fire. All attacks have added fire damage, a Gyrm Greatshield is a good shield to block all of the demon's attacks.