Baldur’s Gate 3: How to Defeat Ketheric Thorm

Ketheric Thorm is the focus of Act 2, but his immortality means that you have to infiltrate Moonrise Towers and find a way to kill him. You’ll accomplish this as you go through the main quests, culminating in a particularly tough boss fight. In this guide we’ll go over how to defeat Ketheric Thorm in Baldur’s Gate 3.

How to Defeat Ketheric Thorm in Baldur’s Gate 3

Ketheric Thorm’s fight has two stages: the first is at the top of Moonrise Towers, and the second is in the Mindflayer Colony.

Fighting Ketheric Thorm on Moonrise Towers’ Roof

If you save Nightsong. The first stage for Ketheric’s battle features a set of adds, but the fight overall is straightforward here. Focus on the adds first. They don’t have a lot of health, so an AOE spell like Ice Storm can usually take out a group in one shot, and there are only two groups along with two single, slightly stronger adds. Although, one is a skeletal dog and it doesn’t do much in the fight.

Keep an eye on Ketheric spawning Incubate Death eggs that hatch into more adds, but they have 14 Health. Try to dedicate a party member to killing them when they pop up. It’s best to have a character tank his hits and focus on using ranged attacks because he’ll retaliate against characters who hit him with melee attacks.

Once Ketheric’s health gets low, the fight ends. He’ll take Nightsong with him into the Mindflayer Colony. You can, and probably should, take this chance to have a Long Rest because you’ll be unable to do so once you enter the colony, where two boss fights await you.

Fighting Ketheric Thorm in the Mindflayer Colony

If you saved Nightsong, Ketheric will start the second stage of his fight Invulnerable. Have a character rush to Nightsong to free her on the right side of the room, and Ketheric’s invulnerability will be removed. She also acts as a tank for your party and can deal her fair share of damage to Ketheric.

After you free Nightsong, this stage of the fight is pretty similar to the first one. Deal as much damage as you can to Ketheric while managing the adds and Incubate Death eggs. The Mindflayers have more Health than other adds, so it’s worth bursting them down since they can be annoying. Once his health is low again, another cutscene plays, ending this stage of the fight. Next up is fighting Myrkul.

That’s most of what you need to know about how to defeat Ketheric Thorm in Baldur’s Gate 3. With the end of Act 2 approaching, check out our BG3 guide hub for content regarding upcoming choices like should you help the Emperor or should you kill Viconia.