This page focuses on Ketheric Thorm's behavior during turn-based combat gameplay.
| Ketheric Thorm | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Medium Undead | |||||||||||||
| Level 11 Paladin Undead | |||||||||||||
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| Stats | |||||||||||||
| Armour Class | 22 | ||||||||||||
| Hit points | 188 | ||||||||||||
| Movement speed | 9 m (30 ft) | ||||||||||||
| Weight | 75 kg (165 lb) | ||||||||||||
| Initiative | +1 | ||||||||||||
| Ability scores | |||||||||||||
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| Proficiency bonus | +4 | ||||||||||||
| Saving throws |
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| Resistances | |||||||||||||
| Immune | Poison | ||||||||||||
| Resistant | Bludgeoning, Piercing, Slashing, Necrotic | ||||||||||||
| Conditions | |||||||||||||
 | Increases Saving Throws to self and nearby allies | ||||||||||||
 | Increases weapon damage to self and nearby allies | ||||||||||||
| Features | |||||||||||||
 | +1 bonus to Spell Save DC and Spell attack rolls. | ||||||||||||
 | Can attack nearby creatures in the dark without disadvantage. | ||||||||||||
 | +1 bonus to Armour Class while wearing armour. | ||||||||||||
 | Immune to disease. | ||||||||||||
 | Make an additional free attack after making an unarmed or weapon attack. | ||||||||||||
 | Immunity to sleep and advantage on saves against Charmed. | ||||||||||||
 | Immune to having your form changed. +5 to saving throws against spells which Banish. | ||||||||||||
 | Melee weapon attacks deal an additional 1d8 Radiant damage. | ||||||||||||
 Honour | Spend a Legendary Action to Hordestrike an enemy when it is attacked by an ally following Deadly Orders. | ||||||||||||
| Magical Plate | All incoming damage is reduced by 2 | ||||||||||||
 | Make a melee attack against an enemy moving out of range. | ||||||||||||
 | When activated, can't be moved against your will, but have Disadvantage on DEX saving throws. | ||||||||||||
| | Use a reaction to knock an attacker Prone. | ||||||||||||
| Overview | Combat |
Attacks and abilities
Range: 24 m / ft 
Conditions and passives
AoE: 3 m / 10 ft (Radius) 
Allies
The encounters with Ketheric may involve the following allies for either side. Detailed information in their respective pages.
Enemy allies
- Susdera
- Necromite
- Intellect Devourer
- Mind Flayer
- Isobel (conditional)
Player allies
- Dame Aylin (conditional)
Encounters
Ketheric Thorm's actual battle has two individual stages, with some of the choices of the party coming into play in them.
Stage 1
The first part of the encounter with Ketheric is atop the Moonrise Towers. Ketheric will be joined by Susdera, an acolyte of Myrkul, as well as eight necromites. Susdera will stand immediately before the party, while Ketheric will stand on the small balcony behind her, necromites flanking the stairs to it on both sides.
The necromites can be safely ignored if the party is equipped to have a high DC or has necrotic resistance, as they only cast Reach from Beyond, a low damage spell. However, both Ketheric and Susdera can summon more of them, so it's best to dispatch them with AoE attacks to avoid being overwhelmed.
Susdera herself may prove to be more of a direct threat at the start of combat given that she can cast Fireball and the party begins the fight grouped together by default. Silence or Darkness spells can neutralize her and give the party a chance to form up as needed. She's also able to cast "Bone Chill", preventing healing for one entire turn.
Ketheric may be a challenge if the party has no means of reliably damaging high AC enemies as he boasts a strong 22 AC. Additionally, though his Dexterity skill is relatively low, he has advantage on Dexterity Saving Throws via Ketheric's Shield. Spell with a dex save component can still be used should Ketheric use Reaper's Embrace, which would negate the advantage he has. Charming or putting him to Sleep is out of the question too given his Fey Ancestry.
Ketheric has relatively low Intellect, so spells with it as a saving throw are a good means of damaging him. Alternatively, players may lean more into the melee side of things and attempt to knock him prone, paralyze him, disarm him or otherwise. Blinding him or other means of granting the party Advantage are also means of getting hit in more reliably.
Ketheric's main source of damage will be through a combination of his melee attacks and Smites. As a Paladin type of enemy, his attacks can very quickly burst down party members if his hits all connect. Radiant damage resist, AC increasing spells and granting him Disadvantage are all methods to mitigate his burst damage somewhat. At the end of his turn, Ketheric will also order his necromites to focus fire using Deadly Orders and cap his turn by casting Incubate Death. Be careful of the AoE explosion of the summoned entity should it not be destroyed before transformation.
Ultimately, the best course of action is to burst Ketheric down as soon as possible through whatever means available. Should the player have spared Aylin, she will join the fight on the party's side and assist. She's capable enough of quickly dispatching Susdera through her own Smites and greatly help with Ketheric.
Once Ketheric's health drops to around 25%, he will interrupt the fight by summoning a gargantuan tentacle, kidnapping Aylin should she be present, and fleeing down the destroyed tower to the Mind Flayer Colony. If all of his allies are dead, combat ends immediately, otherwise they must be dispatched first. The party is then free to explore the surroundings and follow Ketheric when ready.
Stage 2
Phase 1
The second stage of the fight begins shortly after catching up to Ketheric in the Mind Flayer Colony. A Restoration Pod that grants the benefits of a Long Rest can be found to the right of the elevator that brings you to him. After the revelations regarding Ketheric and his allies, players will enter a short conversation with Ketheric. During this dialogue, he can be talked down from fighting with a 
DC 18 Persuasion check. On a success, Ketheric will kill himself and the battle will skip to phase two. Otherwise, a fight will ensue.
This time, Ketheric can be found on the raised, round platform before the party. To the far right, a Mindflayer can be found overlooking the battlefield, further in, four Intellect Devourers will quickly approach the party. Should she be alive, Aylin will be found trapped by spectral hands, granting Ketheric invulnerability once more. To the other side of the room, to the left, four necromites will sling spells down at the party.
Ideally the party should split in three: one to deal with the Mindflayer and help Aylin if alive, one to keep Ketheric occupied and one to deal with the Necromites. Dispatching the Mindflayer quickly will help the party keep control of the battle as otherwise it will attempt to stun them. It will also grant the party member a vantage point to fight against the intellect devourers and Ketheric. Dispatching the intellect devourers shouldn't be too difficult, most AoE spells should work, and they are not too troublesome either, though they could prove an annoyance should they threaten a ranged unit.
Aylin can be broken from her prison via the Help action. Once free, she will assist the party in the fight, usually going directly to Ketheric. The Necromites on the left platform are not too dangerous, however, they should be eliminated before the next phase, otherwise Ketheric will have a great power spike. One party member with an AoE spell should suffice, leaving them up there will also provide another vantage point for the rest of the fight.
Finally, dealing with Ketheric himself should be relatively similar to his first encounter. Beware that much like any other NPCs, he will quickly deplete all his spell slots using Smite on each of his attacks, so any form of mitigating this burst damage is good, such as an Elixir of Radiant Resistance. Like in the previous fight, Ketheric can order his party to focus using Deadly Orders and raise new necromites using Incubate Death.
As soon as Ketheric is defeated, the next and final phase of the fight begins. It's recommended to clear all of Ketheric's allies before moving on to the next phase of the fight.
Phase 2
The last phase of the fight begins as soon as Ketheric is killed, and this time the party faces the Apostle of Myrkul. Twisted by necrotic magic, the Apostle takes up the entire space in the center of the room, summoning necromites as the fight begins.
The Apostle hits hard, often and has a large health pool. However, don't be intimidated as the battle is manageable provided you take care of the necromites and keep the Apostle occupied. The main gimmick of the fight is that the Apostle will sacrifice a necromite in order to gain the Finger of Death spell. Should the necromites be dealt with, or the Apostle itself prevented from consuming them, the threat of the spell shouldn't be an issue.
Despite the large size of Apostle, it's still susceptible to most regular conditions, such as weakened or blinded, and can be made wet using Create Water. The effect from Arrows of Ilmater that prevents healing and similar effects that prevent healing are extremely effective. Casting Darkness on it will help any melee fighters prevent some of the damage and combos particularly well with anyone who can see within darkness. The Apostle's Reaper's Scythe does respectable damage and also knocks foes back, keep this in mind as it's possible it could knock units out of the platform. To prevent this, position all melee units with the spikes of the arena on their back, this way, if they are pushed, they won't fall off. Alternatively, the Apostle can be disarmed of the scythe, removing the threat entirely.
Once he is defeated, he will finally die for good, allowing the party to retrieve his Netherstone, and proceed to Baldur's Gate.
Achievements
No Free Lunches
Defeat the Apostle of Myrkul before it consumes any necromites.
Notes
- If Gale uses his Netherese Orb Blast during the second encounter with Ketheric, the game can end at this very moment, allowing the party to kill Ketheric Thorm, Enver Gortash, Orin the Red and the Absolute in one fell swoop. This only works during the cutscene; using the ability outside of the cutscene will trigger a Game Over as usual.
- Ketheric has Necrotic resistance and Poison immunity on Tactician difficulty.
- If you are an Oathbreaker Paladin above level 11, it is possible to use Control Undead on the Apostle of Myrkul and have him fight for you against his minions. His movement speed of 0 means he will not follow you anywhere to fight anyone out of his range. You could then attack him again and kill him while he remains friendly and won't fight back. This death however will not trigger the cut scene where he turns back to Kethric or the Dream Visitor returns. Looting the body of the Apostle will give you a supply pack, a letter from Isobel, Kethric's Warhammer, and Kethric's Sheild, but not the Reaper's Scythe, Reaper's Embrace or Kethric's Netherstone. This option thus prevents the game from progressing to Act 3.