The Blood Fly spell, or simply the Swarm of Flies, is an offensive Blood Incantation in Elden Ring that requires both Arcane and Faith to cast. This Incantation shares the power of the Lord of Blood, Mohg. Using this spell, you can summon a swarm of blood flies onto the target that deals standard physical damage and builds blood loss to enemies.
The following guide will show you the Swarm of Flies location in Elden Ring and how you can use it to craft an unbeatable Bleed Build.
Swarm of Flies Location
Swarm of Flies is an excellent incantation that comes in mighty handy against some of the hardest enemies in Elden Ring. These flies are known to be born from the waste of the blood swamp. This area is located in the Lord of Blood Palace. However, getting the incantation will be a bit tricky though.
Swarm of Flies can be found inside a cave in the Mohgwyn Palace region that packs a lot of tough enemies. The exact location is marked on the Elden Ring map below.

However, simply walking in might not be the best course of action. You can choose to just teleport in by acquiring the Pureblood Knight’s Medal as a reward for completing Varre’s questline, the main NPC whom you will meet at The First Step Site of Grace.
If you are not interested in completing the aforementioned questline, the other way to reach Moghwyn Palace is through a Sending Gate situated close to the western bluffs in the Mountaintops of the Giants.
This region is opened by overcoming Morgott and gathering the two bits of the Haligtree Secret Medallion, which is utilized at the Grand Lift of Rold to initiate a secret pathway. When Tarnished explorers show up in the Consecrated Snowfield, they should make a beeline for the west and rout an NPC Invader named Sanguine Noble to utilize the entryway to the Mohgwyn Palace.

Once you have passed through the Sending Gate, you will show up in a cavern burrow close to the Palace Approach Ledge-Road Site of Grace. Head down the path toward the north and into the dark red tidal pond. Be aware of the gathering of Albinaurics that monitors this way.
Enter the second sinkhole on the right and loot the corpse on the eastern wall to get the Swarm of Files incantation.
Swarm of Flies Stats

Swarm of Flies incantation in Elden Ring requires 11 Faith and 16 Arcane to cast. You will also need a good Scared Seal and 1 spell slot in addition to 14 FP and 24 Stamina cost.
This spell’s attak power scales with Int scaling of the sacred seal used. As this spell has no specific seal that increases its efficacy, Dragon Communion Seal is the best to go with it.
Swarm of Flies Best Build
As the Swarm of Flies causes bleed build-up, we will be going a bleed build for a level 150 character. For this build, we recommend the following stats.
- Vigor: 50
- Arcane: 70
- Faith: 40
Use a fully upgraded Dragon Communion seal with a +10 Rivers of Blood katana. White Mask of Varre to enhance the attack power after bleeding is induced. For the talismans, go with the following.
With this build, you can easily melt bosses including Malenia despite the incantation being nerfed in the latest patches.