Pestilent Mercury is a Sorcery in Dark Souls 3. To cast a Sorcery you must use a Staff or Special Weapons that can cast Sorceries.

Pestilent Mercury

Spell Type


Focus ConsumptionFocus Cost 13
Attunement SlotsSlots Used 1
Requirements 30 Intelligence
Type Lingering AoE



Highly dangerous sorcery employed by Dragon School spooks. Only taught to trusted members.

Releases mercury that eats away at HP. Beware, as the caster is not immune to its effect.

A body caught in the silent mercury cloud lies still, while the face twists in a tortured scream. The names of these learned sorcerers became feared for this gruesome spectacle.


Acquired From

  •  Can be bought from Orbeck of Vinheim for 1000 souls after giving any sorcery scroll.




  • Acts similar to Lifedrain Patch from Dark Souls II.
  • It deals damage to everything in its radius, including the caster. Try not to stand in it after casting. However, it does not hurt friendly phantoms.
  • This spell doesn't deal poise damage and will not stagger an opponent.
  • Very useful to kill mob enemies such as the Deacons of the Deep or the large crowd of Jailers in the lower level of Irithyll Dungeon, when used in combination with a lure such as an Alluring Skull or Aural Decoy.
  • This spell will not aggro Mimics. 
  • Its damage was increased by 150% in the 1.08 Patch. This makes it a very deadly spell, espically due to the spell having long lasting and large mercury cloud, which pretty much guarantees death for opponents stuck in tight spaces.
  • Damage does NOT increase with Dusk Crown, Scholar's Candlestick, Young Dragon Ring, Bellowing Dragon Ring, any Clutch rings, or the Steady Chant weapon art from staves. (Easily varified against any mimic) 
  • Spell Duration is not affected by Lingering Dragoncrest Ring. (Easily varified against any mimic)
  • Note that while its picture does have the same corroded scroll appearance shared by dark spells, it still gains no scaling whatsoever even when cast with the Izalith Staff. It may be a dark spell in flavor, but it isn't in practice.
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    • 06 Mar 2017 07:30  

      What was once the worst spell in the game has become one of the most powerful!

      If cast while invisible upon foes, they will stand there and parish! Sometimes others enemies just walk into it out of curiosity and parish also!

      Just stay invisible and you can easily destroy powerful foes! NPCs not so much sadly.

      • 19 Feb 2017 05:30  

        Pretty useful as a finisher in PVP. foor those opponents that get dodgy when their HP is low. Bait them by casting it within stone's throw. The temptation to attack you while casting would be too god for them to resist, and they die after passing through the cloud.

        • 08 Jan 2017 15:53  

          They must have patched this. Just tried this out and it did a tone of damage. Sucks you have to be super close. But I got invisible, walk up and drop it on a few knight and they're dead in no time.

          • 05 Jan 2017 16:57  

            Pestilent Mercury also does not aggro sleeping Ravenous Crystal Lizards. Tested it on the sleeping Lizard near the Farron Keep Perimeter bonfire and it didn't move an inch.

            • 12 Dec 2016 02:50  

              The problem with this spell isn't the damage, it's the absolutely tiny range. seems like you can only cast it a few feet in front of you, unlike snap freeze.

              • 03 Dec 2016 23:33  

                When I tried to use this in PvP (pre-buff) my opponent just walked inside the cloud and used the toast gesture.
                During the whole process he took a total of about 40 damage.
                Feels bad ;-;

                • 09 Nov 2016 08:48  

                  I used this with the Storyteller's Staff literally 2 seconds ago on High Lord Wolnir so I didn't have to fight him. The damage amounted to a whopping 2016 (something like 23 damage per tick)! Wow, that is an awesome coincidence. Did this spell receive a covert buff, or somehow gain performance on how quickly it can kill Wolnir? It's never done this high damage before.

                  • 04 Nov 2016 06:46  

                    i used this plus toxic mist to kill 2 sulyvahns beasts near aldritch covenant with invisibility which i found very useful for survival. the poison took longer in effect but pestilent mercury did most of the damage.

                    • 29 Oct 2016 23:39  

                      Tried both dark and magic clutch ring, it still seems to do between 926 and 948 damage on NG+3 mimics with no consistency.... cant be sure if its cause it has to be centered to do max damage. Using +5 crystal chime with 50 faith and int. with all magic rings (young and bellowing dragon crest, magic clutch and sage ring +2) and the candle stick

                      • 21 Oct 2016 14:49  

                        patch of October 21st 2016 has greatly improved the spell, damage has be increased greatly, likely meaning it scales with spell buff now

                        also it continues dealing damage for a couple of seconds after victims leave the mist

                        • Too Niche21 Sep 2016 14:26  

                          I wish this thing wasn't so ***** niche. Has very specific PvE applications which are very gimmicky, and is pretty much a non-factor in PvP. I've only been able to effectively use it once against some guy who parked himself in a nook. He was trying to bait me in, but I stuck the cloud in there and then he decided to come out and fight in the open.<br/><br/>Not really sure what the best way to buff it is aside from giving it more damage. I think the fact that it can hurt the caster can justify a significant damage increase since it would require great care from the caster to not position it badly and end up having to move into it. You basically commit to wanting to control the space so aggressively that you'd be willing to take the risk of the spell dealing damage to you too.<br/><br/>As it is, it's not really useful for making an opponent respect your intimidation attempts involving space control when it barely tickles them. I've even stopped using it to kill mimics because it just takes too ***** long. There's few enough dark magic spells as it is, so when one of them is just lackluster it really hurts.

                          • Awesome29 Jul 2016 22:32  

                            The most underrated sorcery spell. I always use this while Lothric is trying to revive Lorian in the Twin Princes fight and it eats a ton of their health away. It could also be a protective barrier in PVP (don't duel that much) making your opponent very hesitant to attack you, while giving you a chance to hit them with a good pyro attack or soul stream.

                            • Tech29 Jun 2016 01:02  

                              It works well as a smokescreen, diversion, or for controlling distance. Added to a few other mist type spells also makes it a viable threat. Alone, it wont do much damage but its utility is great.

                              • Smokescreen05 Jun 2016 22:51  

                                Will this work as a decent smoke screen for escapes? Say you're running a ninja/assassin build and you're caught out by someone who will obviously wipe the floor with you, so you pop this spell and run far enough for Obscuring ring to activate/hide to use Hidden Body/Chameleon. Is it opaque enough to hide you as you turn tail and run?

                                • PvP use28 May 2016 01:10  

                                  A lot of people seem to be under the impression that this spell is utterly unviable in PvP, to which I could not disagree more. It acts as a deterrent from getting close to you, as even though it does piss poor damage, it still poses a risk to the attacker. That being that if at low HP it will most likely kill them. Most duels I've fought using it I've won simply because my opponents won't get close to me. Not only does it act as a defacto forcefield, but also as a smokescreen for your spell casting, if I had a nickel for how many people died to crystal soul spear simply because I had pestilent mercury up, I'd be a rich man.

                                  • Mimics23 May 2016 21:47  

                                    I want to add this is actually a great, if not slow way of killing mimics. Just put it down on them, and they will not get up to attack you. I've taken out a bunch using this.

                                    • ~200 Damage19 May 2016 05:00  

                                      It's total damage seems to be about 200, provided the target stays in the cloud for the entire duration.<br/><br/>IMO, the damage per tick definitely needs to be higher, especially since it will also damage the caster. It should be a pretty dangerous cloud. As it is, you're kind of better off just casting a few farron darts... and if that's not a sign of how crappy this is, I don't know what is.

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