Crown of the Old Iron King

The Crown of the Old Iron King doesn't boost any of your stats, unlike the Crown of the Sunken King. If you are planning on using spells during any fight, the crown restores your spell uses at a rate of about 20% every two minutes.

Iron Passage

Start from the Iron Hallway Entrance bonfire. Drop down and run past the gauntlet, making your way to the arena of Smelter Demon.

Smelter Demon

SL1 Smelter Demon at Iron Passage, Dark Souls 2: SotFS

This is the magic version of the Smelter Demon at Iron Keep, and it deals mostly magic damage. The boss is weak against dark and lightning. Being up close to the boss would chip your HP because of the magic emanating from the boss' abdomen. Consume an Elizabeth Mushroom to offset the chip damage. Use the Rapier and buff it with Gold Pine Resin.

Defeat the Smelter Demon, exit the arena, and collect the Pharros Mask. The Pharros Mask boosts your fire defense by 100 points, but at the cost of lowering your lightning defense by 100 points. The unintended effect of the helm is that it allows you to perform the Brightbug glitch. The effect of a Brightbug usually lasts for 120 seconds. Equip the Pharros Mask to soak your character in water, consume a Brightbug anywhere, and quit to menu. Upon loading your character again, the effect of the Brightbug should last as long as your character is alive or you don't warp to a different area. While the Brightbug glitch is in effect, you can swap the Pharros Mask out for another helm. The Brightbug glitch is especially useful against some of the more difficult bosses in the game.

Lower Brume Tower

Start from the Lowermost Floor bonfire. Use Smelter Wedge x 4 to deactivate the Ashen Idol x 4 in front of the arena of Fume Knight.

Fume Knight

SL1 Fume Knight, Dark Souls 2: SotFS

Equip the Peasant set, the Mad Warrior Mask, and the Vessel Shield to grant you 15 Adaptability. Use any elemental buff to fight Fume Knight, except for fire because the boss is highly resistant to fire. When in doubt, buff your weapon with Gold Pine Resin or Dark Pine Resin. The Raw Homunculus Mace+10 is recommended because it can cause the boss to stagger for a brief moment, giving you some time to get in one or two extra hits. Don't depend on staggering Fume Knight because during the entirety of the fight, the Homunculus Mace would most likely stagger the boss once. Phase two is the easier of both phases of the fight. During phase two, back away from the boss and bait the delayed, slow horizontal swing that is accompanied by a ringing audio cue. Roll to your left through the swing, position your character behind the boss, and get in one hit. Look for the forward running thrust attack. Roll to your left through the attack, position your character behind the boss, and get in one hit. Roll away from other slash and thrust attacks.

Defeat Fume Knight and collect the Crown of the Old Iron King.

Memory of the Old Iron King

There is little notable loots in the area. You might want to collect Rusted Coin x 3 to help you farm some rare items. Consider summoning Drifter Swordsman Aidel and Steel-willed Lorrie to distract one or two enemies while you cheese the enemies from a distance or look for an opportunity to safely get in a few hits. The Flame Salamanders are vulnerable to poison. Use Poison Arrows with the (Lightning) Short Bow to poison them from a distance.

Sir Alonne

SL1 Sir Alonne, Dark Souls 2: SotFS

This boss is among the most agile bosses in all three DLCs. This is a fight where you should stack as high Adaptability as you can. The boss can rapidly shorten the distance between you and himself. The Raw Homunculus Mace+10 can stagger him for a brief moment, just as it can have the same effect on Fume Knight. However, the attack animation of the Homunculus Mace, and that of the Mace, is rather slow and you can safely deal at most one hit. Furthermore, you are likely to stagger the boss at most once during the whole fight. The Rapier is quicker. The Ice Rapier has a move set almost identical to the Rapier, except that the Ice Rapier has a longer reach than the Rapier. Using the (Ice) Rapier, there are many opportunities for you to safely and rapidly deal two hits to Sir Alonne.

Defeat Sir Alonne and collect a Smelter Wedge.