SPOILERS AHEAD! YOU’VE BEEN WARNED!
The Witcher 3: Hearts of Stone certainly included some interesting boss battles. The Caretaker proved to be quite the challenge and the Wraith from the Painting switched up how players approach a wraith. But, if one fight were to take the cake for nightmarish, it’s Iris’ Greatest Fear. This monster is actually an Ethereal that takes the form of a victim’s greatest fear. So, in this case, you’ll be battling a demonically twisted version (or should we say versions) of Olgierd von Everec.
The fight against this specter takes place at the end of the Hearts of Stone main quest, Scenes from a Marriage. After restoring each of the memories in the painted dream world of Iris von Emeric, you will face off against her most powerful nightmare. Before beginning the fight, make sure to use some Specter Oil on your blade and to equip your Blizzard potions if you have any. Quen is useful since this enemy can do a lot of damage as well as stun you.
The fight isn’t extraordinarily difficult as long as you don’t slip up. You’ll find yourself within a nightmare surrounded by Ethereals all bearing the rotted face of Olgierd. Luckily for you, you only have to fight them one by one. They all follow the same relative pattern, as well. One thing you should keep in mind before starting your assault is to not attack the Ethereals that are not moving. They will not attack you until the one you’re fighting is dead, but if you touch one, it will join the fray, leaving you to have to deal with more than one of these monstrosities at a time.
Keep a distance from the one you’re fighting and wait for it to fade towards you. It will become a swift shadow moving in a straight line to attack you. Side step when it does this and attack. After you connect three times with your blade, the Ethereal will spew some disgusting black attack from its mouth that cannot be blocked. Repeat the pattern until the Ethereal you’re fighting is defeated. It will turn into a swirl of smoke and bring the next one to life.
The Ethereal grows stronger as you defeat each incarnation. This doesn’t mean too much until you get to the final two. Once you’re down to the last two, the pattern changes slightly, making this fight much more challenging.