Leechmonger is one of the simpler bosses in Demon’s Souls, especially if you know how to approach the fight. He is extremely weak to fire, so any attack that deals fire damage will quickly defeat him.
Leechmonger has four different attacks, all of which are easy to avoid. The first attack involves a slow double sweep of his arms, which is simple to dodge. For the second attack, it is important to stay away from Leechmonger’s front, as he performs a quick sucker punch. You can avoid this by rolling away when he swings his arms rapidly, hitting everything in his path. His final attack involves him bending inward and releasing six leeches in all directions. You should avoid this attack because getting hit by the leeches will slow you down and gradually drain your health. Additionally, Leechmonger can regenerate health over time by pulling in the leeches.
How to Kill Leechmonger in Demon’s Souls
To begin the fight, enter the fog gate and descend the platforms until you reach Leechmonger. Before you attack, apply Turpentine to your weapon for extra fire damage, or equip the Dragon Long Sword +1.
Run up to Leechmonger and repeatedly press R1 until he starts swinging. Wait for him to finish his attack before rushing back in to strike again. Since the boss has no real ranged attack, you can back away to heal yourself when needed. Leechmonger should be defeated fairly quickly. If you prefer to use ranged attacks, you can drop down from the platform above him, lock on, and then strike.
Leechmonger will mostly use his leech ball attack against you, which is easy to counter if you have Flame Spray. This allows you to quickly engage him. After defeating the Armor Spider in World 2-1, you can learn Flame Spray.
Using Firestorm on Leechmonger is the quickest way to defeat him. After defeating the Dragon God in 2-3, you can learn Firestorm from Yuria. If you successfully cast a complete Firestorm on him, he will be defeated in one attack if you run directly over him. This move will hit him multiple times, leading to a rapid defeat.
Another effective method is to use a Lava Bow while in Hyper Mode. After defeating the Armor Spider, you can craft a Lava Bow at Blacksmith Ed in World 2-1. To activate Hyper Mode, equip the Clever Rat’s Ring or the Morion Blade, which will increase your health from 30 percent to 140 percent. Once you enter the fog, immediately pull out the Lava Bow and start shooting arrows at Leechmonger. From this distance, he cannot retaliate and will only regenerate health, allowing you to defeat him by continuously firing arrows.
After defeating Leechmonger, you will receive the Wriggling Demon’s Soul. This soul can be used to learn Poison Cloud. When combined with the Thief’s Ring, Poison Cloud can help you defeat certain bosses. Additionally, this soul can be used to learn Saint Urban’s Cure miracle.
