Baldur’s Gate 3 Ketheric Thorm Boss Guide

Baldur’s Gate 3 offers freedom in a way that few other games can even fathom. Every battle, every quest, and every area can be approached in a unique way, and the only limit is your imagination.

Several of the big quests in the game may seem linear, but if you venture outside the box a little bit, you may find other ways to enter and change the nature of the event entirely.

One of those situations is how to approach Ketheric Thorm, the main enemy of Act 2. It seems like Moonrise Tower has just one clear path, but in fact, you have a few ways to get in. Here’s which path is easiest to Ketheric in Baldur’s Gate 3.

Baldurs Gate 3 ketheric thorm boss

Quest Details Up Front

  • Quest Location: Moonrise Towers
  • Quest Length: 2-3 hours
  • Requirements: None, but having the mark of the Absolute will help.
  • Difficulty: 8/10 with the basement fight, 9/10 with the front gate fight. 8/10 with Ketheric phase 1, 9/10 with phase 2 and 9/10 with phase 3.
  • Rewards: General XP and tons of equipment.

Quest Synopsis

Getting to Ketheric involves gaining access to Moonrise Tower. You can do this in two ways, and depending on the route you take, you can see several variations of the quest play out, including having certain characters join you or die.

Brief Walkthrough

  • Step One- Complete the Trials of Shar
  • Step Two- Go to Moonrise Towers
  • Step Three- Choose between going through the basement or charging head-on.
  • Step Four- Engage in the battle in the dungeon or the massive war through the front gate.
  • Step Five- Confront Ketheric.

Extended Walkthrough

Baldurs Gate 3 reithwin town map final release
Image Source: Fextralife

The path to Moonrise Towers is a challenging one, and initially, you may not even know there are multiple ways to approach it. For me, I went through the dungeon to gain entry, so let’s begin there. Keep in mind that you need to have finished the Trials of Shar beforehand for this walkthrough to make sense to you.

You can, in fact, enter Moonrise Towers beforehand; however, you won’t be able to take on Ketheric and instead will be infiltrating it undercover and eventually be sent off to the Trials of Shar anyway, so I generally cut out the middle man there and head straight for the Trials.

Going It Alone

Baldurs Gate 3 moonrise towers
Image Source: RPGInformer

When you first arrive at Moonrise Towers, you’ll immediately be approached by two servants of Ketheric. They will recognize you as being one of them due to your parasite, and you’ll find yourself heading in through the dungeon floor.

Immediately, things will go awry, and you’ll be stuck in a very tough fight involving three wizards and a seemingly unending number of Necromites. The trick here is that the wizards can use an ability called Incubate Death. This caused Necromites to form in an egg-type form, and eventually, they will hatch. The wizards can use this ability for an unending amount of time. The solution then seems obvious, right? Just kill the wizards, and you’ll be able to stop the army of Necromites.

The problem is that if you approach them, they will immediately Misty Step up to the rafters above and start reigning fireballs. If you have some wizards of your own, particularly Gale, it’s time for them to shine. Spells like Fireball will cover an enormous area here and take out multiple Necromites at a time. You can also use Gale to take out the wizards, leaving your melee-based characters like Lae’zel to take care of the Necromites.

Another strategy you can employ is to funnel the Necromites through the gate to the prison. Keep your melee characters back and use any abilities you have that can lure the Necromites. This only works for a small period of time, though, and eventually, you’ll have to take down the wizards. Any abilities you have that can hold an enemy in place will be hugely helpful here and stop them from running away.

Once this fight is mercifully over, you can explore the prison if you’d like and even rescue some of the captives, but that’s not why we’re here. Instead, exit back through the gate you entered to find a staircase. Climb the stairs, and you’ll soon hear a massive fight going on. You’re going to have to join the fight to get to Ketheric, but entering this way is a massive mistake.

A Little Help from My Friends

harpers Baldurs Gate 3
Image Source: Ma Br via Youtube

Instead of charging in alone, exit the Moonrise Towers Prison and make your way around the building. Eventually, you will come across the camp of Harpers. You will be able to talk to each of them and find out about the assault. You will also be able to speak to Jaheira here and actually get her to join your party. This isn’t a requirement, but if you refuse her offer, she can and likely will die. Take Jaheira along with you to avoid this from happening, and get ready for the fight of your life.

I don’t think I’m exaggerating by saying this is one of the hardest fights in the game. It’s also one of the longest, so save beforehand and get ready for a war of attrition. You will have an army at your side, and luckily, the Harpers are up to the challenge. The objective of the start of the fight is to get positioning. Immediately, you will be in a crowded hallway, and you’ll need to free yourself up in order to avoid getting wrecked by AOE spells that your enemies will employ.

Rush your party to the front and take the fight up close and personal while the Harpers and Jaheira provide support from the back. There are a large variety of enemies here, so try to take out the ones that are in groups first. Most AOE spells and spells like Magic Missle will be vital here as your enemies are numerous, and you’ll want to hit as many enemies simultaneously as you can.

You can get overwhelmed in this battle extremely quickly, so take note of the state of the battlefield every time your turn comes around. The Harpers will fall like flies, but you can heal them if you want to keep some extra allies around to survive the waves of attackers coming for you.

Jaheira is a particularly helpful character in this fight if you take her along with you. Her Druidic abilities are extremely helpful, and moves like Thorn Whip can yank enemies onto your side of the fight, which will allow you and the Harpers to make short work of whoever gets pulled in.

Two Paths, One Result

The question you have to ask yourself is whether you want to deal with the fight in the prison at all. The rewards aren’t plentiful, and unless you’re dedicated to saving the Tieflings, there is no reason to put yourself through the pain of the Necromites’ fight. It can also result in you missing out on Jaheira completely, which can affect how the fight with Ketheric goes.

No matter which way you approach Moonrise Towers, you will end up being able to approach Ketheric without issue. The easiest route is to fight alongside the Harpers. If you’re dying to take on the fight in the prison, do it after the fight at the front gate, and you’ll at least guarantee that Jaheira doesn’t die offscreen.

Baldur’s Gate Ketheric Boss Guide – Full Walkthrough

Baldurs Gate 3 ketheric boss
Image Source: Game Guides Channel

Ketheric Thorm is the final fight of chapter 2, and it’s one hell of a battle. There are two ways the battle can go down: with the Nightsong or without. If you free the Nightsong, she will fight alongside you in this battle and make things considerably easier to deal with.

If you killed the Nightsong, then it’s a tough trudge not only against Ketheric but throughout the entirety of Moonrise Towers because the Harpers and Jaheira will be dead. We’re going to assume you did the right thing and freed Nightsong, so travel up to the top of the tower and get ready for a brutal showdown.

Ketheric doesn’t fight alone in this battle and has several companions of his own. You’ll be dealing with a handful of Necromites, a cultist of the Absolute, and also a skeletal dog, which can make this fight confusing on who to approach first.

Ketheric starts on a balcony, and with Nightsong by your side, she will jump right in. Because she isn’t caged anymore, Ketheric is a fully vulnerable human. Nightsong hits for big damage against Ketheric, but she’s vulnerable too, and he deals out incredibly strong attacks that are also capable of knocking both your party and Nightsong down.

Luckily, Nightsong has a ton of health, and you can keep her healed to make sure you have an extra punch to deal to Ketheric throughout. First off, whoever your best melee character is, send them on a mission to take out the Necromites. They don’t deal big damage, but they’re just as much of a nuisance as the fight before.

Next on the docket is the Skeletal Dog, as this enemy can hurt you fast up close. A strong melee character can wreck this enemy, so act accordingly. For your magic specialists, blast away at Ketheric from afar, and if you can get him on his cultist bunched up without hitting Nightsong, unleash your most powerful AOE spells to take a big chunk out of their health.

You’ll want to make sure you’re staying away from Ketheric’s melee attacks, as they can be extremely damaging and one-shot some of your characters with lower health. Any defensive abilities you have are paramount in this fight, namely anything that Shadowheart can conjure up. Luckily for us, we don’t need to take his considerable health bar down completely, as a cutscene will trigger when he’s a little bit below half-health.

Phase 2

Baldurs Gate 3 ketheric thorm
Image Source: RPG Informer

Phase 2 takes place under Moonrise Towers in the Mind Flayer Colony. There is a decent bit to explore here, and some side quests even pay off here, like Wyll’s, but we’re here to finish the fight. The area we’re looking for has a restoration point and an elevator. Take the elevator to trigger a cutscene, and then get ready for round 2.

This battle is even more challenging than the first one, as Ketheric has Mindflayers fighting alongside him in addition to more Necromites. It’s a bit of a mess, but first off, you need to deal with the Mindflayers. They are incredibly powerful and have decent-sized health pools, so get to work with La’zel here if you’ve got her.

She can take them down in 1-2 turns, depending on her equipment. Nightsong is here as well, but she’s trapped in the back right corner of the room. If you’ve got any flight or teleportation spells, use them to get to her quickly and free her, which will take down Ketheric’s invulnerability shield and let her back into the fight.

The Necromites are an issue again, as is Ketheric’s ability to cast Incubate Death to make them spawn consistently. Once the Mindflayers are dealt with, help out Nightsong with Ketheric with three party members, and let your fourth deal with the Necromites. Ideally, your strongest magic specialist will be able to handle the Necromites with a barrage of Magic Missle and AOE attacks. The key here is Ketheric, as we need to take down his health completely this time.

Ketheric hits even harder this time around, but he’s at a severe numbers disadvantage once you’ve dealt with the Mindflayers, and some decently strong melee characters plus Nightsong wailing away will make this fight go fairly quickly once the Mindflayers are done. Once you’ve killed him, yet another cutscene will trigger.

Phase 3

apostle of myrkul Baldurs Gate 3
Image Source: YouTube via Thorusin

This guy just doesn’t know when to die. This time, he transforms into the Apostle of Myrkul, a hulking monstrosity capable of damage you haven’t yet seen in the game. He’s flanked by Necromites on the balcony-like structures, so this is going to be a complex fight.

If you’ve got some spells left to unleash, use them on the Necromites to start the fight. Ketheric will still cast Incubate Death, but the fewer that are up there, the better.

Dealing with this horrific creature is another matter entirely. He can absorb the Necromites and deliver an essential one-hit kill with the Finger of Death spell. This gives you even more incentive to limit the number of Necromites prowling above.

We still have Nightsong with us for this fight, but she is trapped yet again. Send someone to free her, as she’s incredibly valuable here, and you’ll need to deal a lot of damage in a short period of time. Ketheric’s long-range attacks are manageable here, so keep a good distance with most of your characters and wail away.

Your strongest melee character is likely Lae’zel, so have her misty step right to the front of Ketheric and unleash everything she’s got. Typically, she plus Nightsong on the frontlines should be enough to take it down after a handful of turns. Keep healing both of them while launching any multi-hit spells you’ve got left. It’s a war of attrition for sure, and you should save intermittently whenever you nail a big attack. Eventually, Ketheric will fall, and you’ll have completed Act 2.


Question: Can Jaheira die before she joins you?

Answer: Yes, if you approach the Moonrise Towers from the prison, you’ll risk Jaheira being killed off-screen before you can make it to the front gate fight.

Question: Can you attack Moonrise Towers before completing the Trials of Shar?

Answer: No, Ketheric is immortal and can’t be hurt until the Trials are completed and the Nightsong is dealt with.

Question: Does the Nightsong help with the fight at Moonrise Towers?

Answer: Yes and No. She will be present for the fight against Ketheric if you decide to save her, but you won’t have her alongside you during the battle at the front gate beforehand.


There are so many permutations that take place at Moonrise Towers that it’s tough to see all that it has to offer in just one playthrough. This guide should help you make the decisions on which fights are worth doing and which characters are worth saving. There is no wrong path in Baldur’s Gate 3, just a fascinating amount of them which lead to very interesting and very different results.

Continue reading:

Baldurs Gate 3: How to get Halsin To Join Your Party

Baldurs Gate 3: How to Get Jaheira to Join Your Party

Baldur’s Gate 3 Shadowheart Romance Guide: How to Recruit and Romance Shadowheart

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