Slay the Spire 2 Soul Drain Engine — Capture Spirit and Haunt Loop

Published 2026-03-09Updated 2026-09-196 min read

The Necrobinder's most stable engine: Capture Spirit loads your draw pile with Souls, Haunt taxes every Soul played for damage, and Devour Life converts the cycle into Osty scaling.

Souls are the Necrobinder's self-refilling ammunition: 0-cost spell cards that only enter your deck through other cards. The soul drain engine produces them endlessly with Capture Spirit, taxes every cast with Haunt, and ends rooms with Soul Storm — the most stable, beginner-friendly loop the lich has.

The Necrobinder and Osty in Slay the Spire 2
A soul, it turns out, is a 0-cost card. Spend them all.

The production core

  • Capture Spirit (Uncommon, 1) — enemy loses 3 (4) HP; add 3 (4) Souls to your draw pile. Production, cantrip and chip damage on one line. The engine starts here.
  • Glimpse Beyond (Rare, 1) — add 3 (4) Souls to the draw pile. The extra generator once the loop needs volume.
  • Soulbound (Power, 1) — whenever a Soul is created, add a Soul to an ally's pile too (a co-op star; solo, it doubles your own creation rate).

The payoffs

  • Haunt (Power, 1) — whenever you play a Soul, a random enemy loses 7 (9) HP. This is the engine's profit center: a turn spent casting five Souls is forty-five damage you did not aim.
  • Soul Storm (Rare, 1) — 9 damage plus 4 (6) for each Soul in your Exhaust pile. The late-game bomb: every soul ever spent becomes standing damage on this card.
  • Devour Life (Rare Power) — whenever you play a Soul, Summon 1 (2). Osty's HP climbs every cast — the loop feeds your wall.

The loop

  1. Generate: Capture Spirit and Glimpse Beyond load the draw pile with Souls.
  2. Draw into them: Borrowed Time (gain 4 (6) energy now, pay it back this turn) and Invoke fund the turns where ten Souls resolve.
  3. Spend: every Soul played triggers Haunt, Devour Life's Summons, and counts toward Soul Storm — while costing nothing.
  4. Repeat: the Souls recycle through your discard pile like any cards; production keeps the pile stocked.

Building it

The deck is deliberately pure: generators, Haunt, Soul Storm, Devour Life, energy enablers, and the standard Necrobinder walls. Delete basic Strikes early — Souls and the cards that make them are the whole plan (see deck thinning). Osty sits in front of your 66 HP all game; Bone Flute (2 Block whenever Osty attacks) turns his swings into armor while the soul engine grinds.

The build's charm is that it never forces a decision: production is always good, spending is always free, and the payoffs stack quietly in the background. When Soul Storm starts hitting for triple digits against an exhaust pile full of spent souls, the lich is just doing accounting.

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