Eternal Darkness is a forbidden spell of Sellia, Town of Sorcery. This sorcery draws in spells that are cast around it, keeping the user safe from enemies who use spells. The caster can also safely cast spells without them being affected. This spell is very useful against invaders who use a lot of magic. Here is where you can find the Eternal Darkness sorcery in Elden Ring.
To obtain this sorcery, you will need to travel to the Caelid region. Caelid is the region to the east of Limgrave and the Mistwood. You will know you are in the right area when the ground turns a reddish color. You can also access this area quickly by using the teleportation chest in the Dragon-Burnt Ruins in Limgrave.
Once you reach the Caelid, travel east to the town of Sellia. You will need to get to the mountains above Sellia. This can be done in two ways. You can either go around the cliffs to the west or through Sellia if you have the gates unlocked. Travel up the hills and go to the Sellia Gateway. This is the large gate that is south of Sellia. Instead of going through the gate, you will need to go through the upper level of the gateway to get to the other hill across from you. After going through the gateway, head north to find the Swamp Overlook Tower. The sorcery can be found inside guarded by a Bloodhound Knight. Be careful, the Bloodhound Knight can inflict a lot of bleed damage.
