Cornyx (Cornyx of the Great Swamp) Dark Souls III Guide
Last update: 11 May 2016
Undead Settlement
In order to encounter Cornyx you must leave the room with the Cliff Underside bonfire. Go up, to the place shown on the screen. From this side you can go up and deal with few bombs throwing undead, one after another.
Now go to the corner in which you will find Cornyx in a cage. Speak with him and ask for pyromancy lessons - he will move to the Firelink Shrine.
Firelink Shrine
Cornyx can be found on the right from the blacksmith. During the first conversation you will receive the Pyromancy Flame from him. The second conversation will give you the Welcome gesture. Cornyx is a trader and pyromancy teacher. By giving him pyromancy tomes found in various parts of the world you will learn new, more powerful spells from him.
Cornyx won't accept the Quelana Pyromancy Tome or the Grave Warden Pyromancy Tome. You can give them to another teacher, found in Irithyll Dungeon.
Note: If during the battle with the Old Demon king you summoned a character named Cuculus for help and its phantom survived the battle, it will return to the cage in which you found Cornyx - there will be new items available there.