Ansur (Boss) | Baldurs Gate 3 Wiki

Ansur "Heart of the Gate" Level 17 Undead Dragon
Location	Dragon's Sanctum
Act	Act 3
Quests	The Blade of Frontiers

Ansur is a Boss in Baldur's Gate 3 (BG3). BG3 Ansur is a Level 17 Undead Dragon. He is related to The Blade of Frontiers companion questline as well as the achievement Crash Landing.

Bosses in BG3 are powerful enemies that have increased health and pose a bigger challenge for players.

Where to find Ansur in BG3

Act 3

• Wyrm's Rock Fortress
  
  • Wyrm's Rock Prison
    
    • The Wyrmway
      
      • Dragon's Sanctum (X:-634, Y:-990)

BG3 Ansur Quests

• The Blade of Frontiers

BG3 Ansur Dialogue Options

• N/A

'Crash Landing' Achievement

"In the Wyrmway, wait until the dragon is mid-flight, then knock it out of the sky - KAPOW."

Your initial instinct may be to nuke the boss down within the first two Rounds of combat.  Resist this urge.  You'll want to bait out the first damage phase, making sure not to take Ansur down to 50% hit points.  The reason for this is as soon as he casts Gathering Storm he gains Resistance to ALL damage types.  Even with abilities like Brand the Weak from Amulet of Branding, which afflicts the target with Vulnerability to Bludgeoning, Piercing, OR Slashing damage, or using Diluted Oil of Sharpness, you're unlikely to burn through another 50% worth of hit points on the boss quick enough.

Instead, chip Ansur's hit points down to about 75% for the first Round of combat before letting loose and really leaning into him during the second Round.  By the time he takes to the air with Gathering Storm during the third round of combat his hit points should be low enough to get the final kill.

Elixir of Lightning Resistance will be your best friend for this encounter.  While it may not be effective against the Cold damage from the Water Myrmidon's, it will give you some breathing room with Ansur's Lightning based attacks like his signature Lightning Breath and obviously his gimmick ability: Waiting Storm.

After dealing damage to him with Arrow of Dragon Slaying in Round one, you'll want to pop your Haste spells or Potion of Speed during Round two and keep using Arrow of Dragon Slaying.  Once he starts hovering in Round three you'll then want to use Diluted Oil of Sharpness on your ranged weapons to bypass his Piercing Resistance.

Utility spells like Misty Step, Dimension Door, and Longstrider are also boons for this fight as they allow you to get out of melee range from Ansur or his Water Myrmidon's, enabling you to reposition to be within striking distance and shake off any Disadvantage that might be bestowed upon you from the Threatened condition.

TL;DR Step-by-Step

Round 1 Only use Arrow of Dragon Slaying to chip Ansur's hit points down to ~75%

Round 2 Pop your Haste spells or Potion of Speed to double your Action economy and continue only using Arrow of Dragon Slaying

Round 3 Apply Diluted Oil of Sharpness to your ranged weapons and continue using Arrow of Dragon Slaying while taking advantage of your increased Action economy to kill Ansur and proc the achievement

Round 4+ Finish mopping up the Myrmidon's whilst you still have Diluted Oil of Sharpness and Potion of Speed or Haste active, complete the encounter, and collect your loot

Recommended Gear, Loadouts, and Party Composition:

Minsc, Laezel, Wyll (if you want unique interactions or are doing this as part of the questline from Uldur Ravenguard), Astarian

Ideally you'll have at least two Rangers with the Hunter subclass and one Rogue with the Assassin subclass

Helms: Mask of Soul Perception

Cloaks: Cloak of Displacement, Cloak of Elemental Absorption, Cloak of the Weave

Gloves: Gloves of the Balanced Hands, Gloves of Dexterity

Boots: Blackguard's Greaves, Boots of Genial Striding, Disintegrating Night Walkers, Spaceshunt Boots, Swiresy Boots

Amulets: Amulet of Greater Health

Rings: Crusher's Ring, Ring of Free Action, Risky Ring, Shadow Cloaked Ring, The Sparkswall, 

Weapons: Bow of Banshee, Crossbow of Arcane Force, The Dead Shot (Very Rare Longbow), Harold, Hellfire Hand Crossbow, Ne'er Misser

Ammunition: x30 Arrow of Dragon Slaying

BG3 Ansur Boss Guide

Notes and Tips

• Related literature: The Legend of Ansur
• Ansur's boss encounter only starts once you interact with his corpse.  As such you can loot the Helm of Balduran before starting combat
• If you swap to a different character while you are engaged in dialogue with Ansur on another, you can actually loot Balduran's Giantslayer off his undead corpse