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How to kill Ketheric Thorm in Baldur’s Gate 3

Stock up on snacks and prepare your party. This boss fight will take you on quite the journey.

The player speaks with Ketheric Thorm during a fight in Baldur's Gate 3
Image credit: Larian/VG247

Baldur's Gate 3 is one huge adventure to embark on, with plenty of larger-than-life characters to meet. One such character is Ketheric Thorm, and if we want to lift the shadow curse that is destroying the land, we’ll want to kill him.

That said, this particular bad guy takes you on quite the wild goose chase across Moonrise Towers, and he’s no easy feat to take down. He is immortal, after all, but we’re going to make sure that he ends up dead, for good. Without further ado, here’s how to kill Ketheric Thorm in Baldur’s Gate 3.

How to kill Ketheric Thorm in Baldur’s Gate 3

The battle to kill the immortal Ketheric Thorm is a long one, so strap in and be sure to grab yourself plenty of snacks - and water - as we’re going to be here for a while.

First things first, we want to recruit the help of Jaheira and the Harpers for this fight. It’ll make things considerably easier, so be sure to speak with her when you reach Last Light Inn.

In addition, we recommend finding (and freeing) the Nightsong ahead of this fight so that she can battle alongside you, and speaking with Isobel at Last Light Inn. With that taken care of, make your way to Moonrise Towers via Reithwin Town, shown on the map below.

A map detailing the location of Moonrise Towers in Baldur's Gate 3
Here’s where you can start the assault on Moonrise Towers. | Image credit: Larian/VG247

When you approach Moonrise Towers, you’ll find Jaheira again, ready to kick the battle off. She’ll help you regardless, but here, you can convince her to join you specifically; if successful, you’ll be able to control Jaheira in battle, rather than leaving the AI to their own devices.

Advance into the main floor when you’re ready to start the first portion of this fight. You’ll be facing a bunch of cultists and other creatures, including Disciple Z’rell, but all in all, it’s not too troubling; focus on peppering away at groups of units with AoE and ranged attacks, and you’ll be more than fine.

I also recommend keeping your units spaced out from one another where possible, as these enemies will try using their own AoE attacks, too.

Once that battle is done, you want to make your way to the very top of the tower by pressing ahead into the throne room and up the stairs behind it. There’ll be a small battle here, then you’ll be able to enter the Ornate Door on the left, where you’ll be met with Ketheric Thorm.

The player faces a large ornate door in Moonrise Towers in Baldur's Gate 3
Ketheric is ahead, so prepare yourself in advance. | Image credit: Larian/VG247

You’ll have some dialogue with Ketheric, where you can try to convince him to stand down if you succeed with some very high Persuasion checks.

The player speaks with Ketheric Thorm at Moonrise Towers, attempting to convince him to surrender in Baldur's Gate 3
Image credit: Larian/VG247

Regardless of whether or not you bring Ketheric to his knees, Nightsong will swoop in and interrupt, revealing that Ketheric would never surrender like this. It then becomes clear that for any of this to end, we must fight and kill Ketheric. Alas, the first phase of our three-part battle ensues.

Fighting Ketheric Thorm at Moonrise Towers

This phase of the fight is least troubling. You’ll be fighting Ketheric, a skeleton dog called Squire, lots of annoying Necromites, and the person spawning them, Susdera.

We recommend focusing on taking Susdera and the Necromites down first so that you don’t become overwhelmed. When she’s down, clear the remaining Necromites, then focus on Ketheric and his dog.

Ketheric will bash anyone who tries to attack him at melee range, so ranged attacks and spells are best for this particular enemy. Nightsong, also known as Dame Aylin, on the other hand, will get to work attacking him.

When he eventually reaches under half of his HP (which won’t take long with Nightsong around), he’ll flee, taking the Nightsong along with him into a chasm. That’s not good…

The player party faces a chasm in a Hollow Tower at Moonrise Towers in Baldur's Gate 3
Head into this chasm to continue the fight. | Image credit: Larian/VG247

Speak with Jaheira once more after this fight, and then dive into the Hollow Tower chasm. You’ll now find yourself in the Mindflayer Colony, where everything is suddenly very fleshy and very gross.

Fighting Ketheric Thorm in the Mind Flayer Colony

In the Mind Flayer Colony, take the first door on the left you come to. You’ll reach the Tapoling Centre. We recommend spending some time here and rescuing Zevlor, as he can help us with our continued fight later.

If you free him from the pod you find him in, this will trigger a small battle with some Mind Flayers that you’ll be freeing from the other pods simultaneously, but they’re no trouble at all.

Once that’s all taken care of, you’ll want to venture east of the Colony over to coordinates X741, Y-23 where you’ll find an elevator and restoration point. This elevator will take us to the next portion of the Ketheric Thorm fight, so make sure you’re prepared!

The player faces an elevator in the Mind Flayer Colony that is beside a restoration point in Baldur's Gate 3
When you’re ready, take the elevator to the next phase of the fight. | Image credit: Larian/VG247

In the back-right corner of the next arena, you’ll see the Nightsong chained up. While battling it out, you want one of your characters to make their way to her and to free her, so she can continue to help us with our fight; if you have Misty Step or a similar spell, one of your characters should be able to teleport over to her.

Nightsong will focus on Thorm, so that your party can focus on the Mind Flayers and Necromites. The Mind Flayers hit hard, while the Necromites’ damage stacks up quickly, so you’ll want to take care of them first. Also, try not to use your most powerful spells just yet, as these are much more important for the next phase of our fight.

You’ll also want to try and keep your party healed here, as you will struggle to heal during the final phase of the fight!

Once Ketheric Thorm reaches 0HP, you’d think the fight would be over. Alas, Ketheric is not done with us yet; he’ll transform into the Apostle of Myrkul, and this is where things get serious.

Fighting Ketheric Thorm as Apostle of Myrkul

This fight is incredibly tough. With Myrkul’s Presence active, you might’ve already noticed that everyone nearby is afflicted with Bone Chill, so your party can’t heal. This means that if they’re downed, they’re staying there or returning with 1HP, which isn’t super useful.

The player is amidst a battle with Apostle of Myrkul in the Mind Flayer Colony in Baldur's Gate 3
This fight is tough, but at least Myrkul doesn't move. | Image credit: Larian/VG247

In addition, Apostle of Myrkul can deal devastating amounts of damage. If your party isn’t quite up to the task, they can be downed in a single attack. Your only option here is to use the spells and attacks in your arsenal that deal the most damage, and to use them quickly. You’ll also want to keep your party spread out, and have one member tank as much damage as possible.

I positioned my spellcasters on the platforms either side of Myrkul, with my melee fighters below the platform he was standing on; I’d have them climb the flesh to his platform, attack, and then retreat back down again so they didn’t take too much damage. This wasn’t always possible, which is why a solid tank is good to have.

I also used ranged attacks for much of the fight, and that Moonlight Glaive we should’ve acquired earlier is great here with its Radiant damage.

As if that isn’t enough to think about, you want to also make sure that you’re chipping away at Ketheric’s minions and Incubate Death Eggs, or else the damage your party receives will add up quickly. On top of that, he’ll heal off of his Necromites, so it’s very important we keep these guys to a minimum.

The player party faces the corpse of the Apostle of Myrkul after a fight in the Mind Flayer Colony in Baldur's Gate 3
Image credit: Larian/VG247

That said, once you finally deplete the Apostle’s health here, Ketheric Thorm will be felled. You’ll be able to grab the following rewards from his corpse:

  • Ketheric’s Warhammer
  • Ketheric’s Shield
  • Ketheric’s Netherstone
  • Reaper’s Embrace
  • Supply Pack

With Ketheric Thorm killed and his Netherstone acquired, it’s time for you to finally make your way to the city of Baldur’s Gate. Also, be sure to speak with Jaheira in Moonrise Towers main floor first, as you'll now be able to recruit her for your camp.

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