Lagavulin Matriarch is a 222 HP Act 1 Underdocks boss who opens with 12 Plating and 3 turns of Asleep. Those three turns are silent: her only move while asleep is Sleep, which deals nothing. So the fight starts with 222 HP of free setup before she throws a single attack.
She sits in the middle of the Underdocks pool — 222 against Soul Fysh’s 211 and Waterfall Giant’s 240 — which is why the correct play is usually to spend the sleep turns on scaling and then kill her in one or two cycles after she wakes.
The fight at a glance
| Act | Act 1 — Underdocks |
| Type | Boss |
| HP | 222 (233 on Ascension 10) |
| Starting powers | 12 Plating, 3 Asleep |
| Free turns | 3 (Sleep deals 0) |
| Biggest hit | Slash 19 (21 on Ascension 10) |
| Cycle damage after waking | 49 over four turns |
Every move, with numbers
| Move | Intent | Damage | Ascension | Other effect |
|---|---|---|---|---|
| Sleep | Sleep | 0 | 0 | No effect — this is the free turn |
| Slash | Attack | 19 | 21 | Single hit |
| Slash2 | Attack + Defend | 12 | 14 | Gains 12 Block |
| Disembowel | Attack | 9 × 2 = 18 | 10 × 2 = 20 | Two hits |
| Soul Siphon | Debuff + Buff | 0 | 0 | Cached record lists +2 Strength on herself |
Four moves after waking and only three of them deal damage, so the rotation is not a damage race in the way Aeonglass is. It is a race against her own scaling: every Soul Siphon adds 2 Strength to her, and every Slash2 adds 12 Block in front of your damage.
The three sleep turns
Asleep is set to 3 at combat start. While it holds, her move list is effectively only Sleep.
| Turn | Her move | Damage | What you should be doing |
|---|---|---|---|
| 1 | Sleep | 0 | Play every Power in hand. No block needed. |
| 2 | Sleep | 0 | Second Power or a big setup card. Still no block. |
| 3 | Sleep | 0 | Last free turn. Bank block if you have Retain, otherwise draw. |
| 4 | First wake move | 19 (21) | Now you need 21 Block from a standing start. |
This is the whole reason the fight is rated easy for its HP total. A deck that needs three turns to assemble its engine — Defect orb scaling, Regent Forge, Necrobinder Summon — gets those turns for free. A deck that opens with 40 damage and no setup gets less value, because 40 damage into 222 HP is 18% of the pool and she still has 12 Plating up.
Damage maths
| Turns to kill (from turn 1) | Damage per turn needed | With 3 sleep turns burned |
|---|---|---|
| 3 | 74.0 | Not realistic without a burst hand |
| 5 | 44.4 | 2 attacking turns at 111 each |
| 7 | 31.7 | 4 attacking turns at 55.5 each |
| 9 | 24.7 | 6 attacking turns at 37 each |
Because three of those turns are free, the real requirement is the last column: a 7-turn kill only needs 55.5 damage per attacking turn. For scale, Bludgeon is 32 for 3 energy and Bury is 52 for 4, so two heavy attacks plus a Strike covers a 55-damage turn without any scaling at all.
The Ascension step is +11 HP (222 → 233), a 5% increase that is smaller than the +2 she gains on every Slash.
What Soul Siphon actually does
This is where the old write-ups drift. The cached move record for Soul Siphon is a Debuff + Buff intent with a +2 Strength power entry targeting herself — not a Strength and Dexterity drain on you.
That still matters, because Strength on a 19-damage Slash compounds:
| Soul Siphon casts | Slash (normal) | Slash (Ascension) |
|---|---|---|
| 0 | 19 | 21 |
| 1 | 21 | 23 |
| 2 | 23 | 25 |
| 3 | 25 | 27 |
By the third cast her Slash is doing more than her opening hit on Ascension. The fight does not get harder because she debuffs you; it gets harder because her numbers go up while yours stay flat.
Turn-by-turn after waking
The post-wake cycle is Slash → Slash2 → Disembowel → Soul Siphon, 49 damage over four turns (53 at Ascension: 21 + 14 + 20 + 0).
| Turn | Move | Incoming | Block needed |
|---|---|---|---|
| 1 | Slash | 19 | 19 (21) |
| 2 | Slash2 | 12 + 12 Block on her | 12 |
| 3 | Disembowel | 18 in two hits | 18 (20) |
| 4 | Soul Siphon | 0 | 0 — free turn, play attacks |
Turn 2 is the trap: 12 damage is trivial, but her 12 Block means your attacks lose 12 points of value that turn. The free turn is turn 4, where Soul Siphon deals nothing and you can dump a full hand of attacks into her.
“Slash — Attack, 19 damage (21 at Ascension). Soul Siphon follows and adds 2 Strength.” — STS2 boss data, slaythespire.wiki.gg
What to bring
- Powers you would normally never have time to play. Three sleep turns is the widest setup window of any Act 1 boss.
- One big attack, not many small ones. 222 HP falls to two 50+ hits; a hand of 6-damage Strikes needs 37 of them.
- Retain block. Banking turn 3’s block into turn 4’s 21-damage Slash is free value.
- Strength on your side. Her +2 per Soul Siphon is a scaling clock; matching it with your own Strength keeps the kill inside seven turns.
Where to go next
The boss table ranks all twelve rooms by HP, and the monster index lists every Underdocks encounter. For deck construction, the cards database has the cost and upgrade for every heavy attack, the relics database covers the Plating relics, and deckbuilding basics explains how to build a three-turn setup.