Koshchey’s Core
Koshchey’s Core is a mutagenic potion in The Witcher, made from the Koshchey heart, a rare part taken from a powerful monster. Drinking it changes Geralt permanently: he gains one Gold Talent to spend on his development.
To brew it, Geralt needs the recipe and the Koshchey heart, plus 1 Aether and 2 Hydragenum on an alcohol base. Like other potions, it is prepared while meditating at a fire or an inn.
Keep exploring
Plan a Remastered build: skill trees, mutagens, gear and a shareable build image.
Pick a potion, decoction or bomb and see every ingredient you need.
Answer the key choices and find out which Witcher 3 ending you will get.
Every location, quest and monster in the first region on one map.
The Wolf School's hidden valley: the keep, the Bastion, caves and treasure.
Tick off every school gear diagram and crafted piece, with diagram locations.
Search any monster and see the right oil, Signs and bombs.