I drank tawny owl, swallow, and petri's philter (+ sign intensity)First I casted Quen to protect myself, then I draw Yrden before the Koshkey (Quen keeps protecting while you do that)then I walked backwards. The Koshkey walks over the Yrden sign and gets thrown backwardsthen I just kept casting Igni, the koshkey could not reach me, and he was soon a fried chicken!Hope it helps!