The world of Baldurs Gate 3 is full of evil bosses for you to defeat, and at the end of Act 2, you will need to defeat Ketheric Thorm. However, doing this is much easier said than done, as he is one of the hardest bosses to defeat in the game, primarily as he is a necromancer and has mastery over death! In this guide, you’ll learn how to defeat Ketheric Thorm in just a few simple steps.
Finding KEtheric Thorm
Finding Ketheric Thorm shouldn’t cause you too much trouble. He’s the centerpiece of your time in the Shadow-Cursed lands and resides in Moonrise Towers. So, head here to find him.
Once you’ve reached Moonrise Towers, Ketheric Thorm will be there waiting for you. Though, he won’t yet be hostile. And as long as you pass the right dialogue checks, he will let you through and give you a few neat quests to complete.
Your primary goal while in Moonrise Towers is to infiltrate the cult, so a stealthy and subtle approach is advised. Keep exploring Moonrise Towers, and you will come across Balthazar’s diary. Reading this will tell you to go to Thorm Mausoleum to find the Nightsong. The Nightsong is the best way to defeat Ketheric Thorm in Baldurs Gate 3, so finding this is now your top priority.
Make your Way Through the Gauntlet of Shar
Make your way over to the Thorm Mausoleum. When you arrive, you’ll be presented with a mini-puzzle. To complete this, just press the Moonrise Towers button first, then the Grief painting, and finally the General Painting. Doing so will allow you to enter the Gauntlet of Shar. But this area is very dangerous.
During your time in the Gauntlet of Shar, you will need to find four Umbral Gems. Firstly, to unlock the first gem, complete the soft-step trial, which is a difficult maze. To unlock the second gem, complete the Self-Same Trial, which is a fight against yourself. To unlock the third gem, complete the Faith-Step trial which is a journey across an invisible pathway that you’ll have to traverse successfully.
Finally, to obtain the fourth gem, head to the chamber of Orthon Yurgir. Depending on your playstyle, you can take the gem by force, break his cursed contract, or convince him to kill himself. Choosing the last route is probably the easiest, as you’ll avoid any kind of conflict entirely. And there will be more than enough conflict when you do go on to defeat Ketheric Thorm.
After you’ve collected the fourth Umbral Gems, head over to the Silent Library and clear it of enemies. Then, destroy the Silence Portal in the room. This will give you your magical powers back.
Next, search the bookshelves until you find something called “Teachings of Loss: The Nightsinger,” making sure to avoid any traps. Use perception checks to reveal buttons around the room, and once you’ve clicked all of them, an inner cage will be revealed. Place the Teachings of Loss inside this cage. This will unlock access to a room holding the Spear of Night, which is a key tool in your quest to defeat Ketheric Thorm.
Finding the Nightsong
From here, it’s time to use the Umbral Gems that you collected earlier. Go to the center of the Gauntlet of Shar and place your first Umbral Gem in the Ancient Pedestal. This will send the platform to the Gauntlet’s underbelly. Then, insert the last three gems, which will unlock the path to the Nightsong Prison.
As you jump down the rocks, you’ll encounter Balthazar. You can choose to give him the Nightsong or engage him in battle to save her. It’s recommended that you fight Balthazar, as Nightsong is a powerful ally and will make defeating Ketheric Thorm much easier.
Once you’ve dealt with Balthazar, head over to the Nightsong. You will have a choice of killing her or saving her, but as previously mentioned, she is a valuable ally, and killing her would be a huge mistake.
Saving Nightsong is as simple as placing your hand around her and setting her free. It should be noted that Shadowheart will want to kill the Nightsong, and saving her may turn her against you. However, this shouldn’t deter you, as Nightsong is a much more powerful ally.
Once you have recruited the Nightsong, you’re finally ready to defeat Ketheric Thorm
How to Defeat Ketheric Thorm
Make your way back to the Moonrise Towers. The cult of the Absolute, who found out you betrayed them, will confront you. Before you engage, the Harpers will join you to make the battle a little easier. By allowing them to join you in the fight against Thorm you will be able to recruit the character Jaheira
After defeating the Cult of the Absolute, head to the upper floor of Moonrise Towers. This will initiate the first phase of the Ketheric Thorm battle. Defeating him in this phase is actually really easy, but after you take him down, he will escape down a fleshy hole.
As you track down Thorm, you’ll be able to explore the Mind Flayer Colony, giving you the opportunity to free captured allies such as Zevlor. Once you’ve done this, head to the Arena- Thorm will be waiting.
In the arena, free the Nightsong before doing anything else. Then, keep hitting Thorm with spells from a distance, and save your game every time you make a dent in his health. This way, you’ll be able to revert back if anything goes wrong.
Over time, you will finally defeat Ketheric Thorm. This will mark the end of Act 2 and you’ll immediately head into Act 3, which is full of even more dangerous enemies.
Defeat Ketheric Thorm – Final Thoughts
Ultimately, defeating Ketheric Thorm is a very difficult and long-winded process. But, the rewards are worth the effort. For completing this specific quest we will be rewarded with the Ketheric Thorm Netherstone