The
Yharnam, Pthumerian Queen trophy is awarded for killing Yharnam, the Blood Queen of the Old Labyrinth. She is the final boss of the
Pthumeru Ihyll Chalice Dungeon, the deepest dungeon in the Pthumeru dungeon set.
Residing at the end of the third layer in the dungeon, Yharnam is not as fast as the
Pthumerian Descendant from the first layer, nor is she as strong as the
Bloodletting Beast from the second layer. If you handled either of those bosses with ease, you should be able to handle the Queen.
When you enter her chamber, Yharnam will be standing in front of a
large stone monolith that dominates the center of the room. Her arms are initially chained together, preventing her from effectively attacking you physically. At range she will attack primarily by
shooting poisonous blood shots at you, usually in an arc left to right and back again or vice versa. She can also fire off
large blood explosions when you move in. If you get too close to her you will start to hear the cries of her baby, the unborn Mergo. If you stay near her after the crying starts, you will be
immobilized (like when fighting a Brainsucker), allowing her to attack you up close.
Once you chip away a third of her health, she will break her bonds and
unsheathe a sharp knife. Be careful - in addition to attacking you with it, she will stab herself with this blade, summoning
powerful blood spears that will shoot up out of the ground underneath you, doing lots of damage. Quickly dodging and strafing around her, dodging in briefly to strike, should keep you safe. She can also enlarge her knife with blood magic, creating a blood sword before
quickly hovering over the ground to attack you. This is her fastest move and its easy to dodge so just keep an eye out for her enchanting her sword.
As you do more damage, she will tactically retreat,
disappearing into the ground only to emerge at a random location in the arena, joined by
two identical apparitions of herself. To tell the real boss apart from her clones, simply look at her stomach. Unlike when you encounter her in the main game, Yharnam is still
pregnant here; her doubles are not and will die with a single hit. As long as her clones are alive, each will attack you with ranged attacks, using variations on the blood shot attacks from before. Use the center stone monolith to your advantage here; it will block the attacks from any of the Queens on the far side across from you.
Once she's down to a third of her health remaining, she will change tactics yet again, employing more powerful blood attacks. She'll use a
blood eruption attack similar to the Firestorm pyromancy from Dark Souls. She'll also summon more blood spears, casting fast moving lines of them across the arena. During some of these attacks it is possible to get behind her to execute a charged heavy attack; this will often stun her, opening her up for a visceral attack. Take advantage of these opportunities when you can.
Overall, her attacks follow set patterns that are easy to learn and anticipate, allowing you to avoid her worst attacks while letting you to get in close during the gaps to get a few strikes in. Always be aware of when Mergo starts crying; you can usually get two strikes off against her when the crying starts. Going for three is likely to get you caught but four will definitely trap you, so don't be greedy.
For more information on this boss fight and for some tips on how to get the materials necessary to conduct the Chalice ritual for the dungeon, see the following video from
PS4Trophies: