Boss Fight: Iris' Greatest Fear - The Witcher 3 DLC Hearts of Stone Guide
After the Boss Fight: Wraith from the Painting and all the other fights with the Specters it's time to fight the Boss: Iris' Greatest Fear. You've taken Down all the specters, Used Witcher Sense to examine the areas and solve the painting puzzles. Here we have to face the Iris' Greatest Fear the Boss fight in The Witcher 3 DLC Hearts of Stone.
Once the Snow pops out of the painting and You are outside, do not waste time admiring the scenery and to find an open cellar hatch just head right of the steps leading to the house. Use Witcher Sense to examine the area(door at the end) and collect all the items littered about the place, put the mug in Olgierd's hand, the marriage contract in Iris' father's hand and get ready to face off the spectres.
Head upstairs and Use Witcher Sense to examine the room and start collecting the items and place the large bowl in front of the dog, the small bowl in front of the cat, and the food tray in the caretaker's hands. Now get to the marker and read the letter on the table, and then prepare to face the next Boss Fight: Iris' Greatest Fear.
Boss Fight: Iris' Greatest Fear
Here you'll be facing several undead Olgiers who attack one at a time. They have a very fast move and attacks skills so you need to focus more on defence instead of attacks. The Big Boss is sensitive to specter oil and Blizzard potion. To defeat him you need to perform a combination of dodging, parrying, and running for a quick flurry of attacks should minimise the threats. Later after the Defeat speak to Iris and take the rose to complete the quest.