The Necrobinder is one of two brand-new characters in STS2 and currently sits in S-Tier. She fights alongside Osty, a giant reanimated skeletal hand, and commands unique mechanics including Doom execution, Soul draw engines, and Summon health stacking. This guide covers three proven archetypes with specific card picks, relic priorities, and gameplay strategy.
The Necrobinder starts with Bound Phylactery as her starting relic, which summons Osty at the start of each combat. Osty starts at 1 HP, absorbs all incoming attack damage via "Die for You", and can be buffed with the Summon keyword. If Osty dies, he reassembles on your next turn.
Her unique mechanics include Doom (an execution threshold — when enemy HP ≤ Doom stacks, they die instantly), Souls (0-cost cards that draw 2, generated by other cards), and Summon (adds HP to Osty). These three pillars form the basis of her three main builds.
Stack Doom on enemies until their current HP drops below the Doom threshold, then they get executed instantly. Think of it like Poison on steroids — except it's a kill switch, not damage over time. The most satisfying way to kill elite bosses in the entire game.
Pump Osty's HP pool high enough that he becomes an indestructible wall, then use Osty-specific attack cards to deal massive companion-based damage. Since Osty's HP functions like Block that doesn't wear off, this is effectively an infinite defense build.
Turn 0-cost Soul cards into a turbo draw engine, then use Haunt to make Souls directly damage enemies. This build thins your deck to 5-10 cards and cycles through your best plays every single turn. Glass cannon but devastatingly fast.
| Priority | Relic | Why |
|---|---|---|
| Must-Pick | Bone Flute | 2 Block per Osty attack. Free defense in every build. |
| Must-Pick | Undying Sigil | Doom ≥ HP = enemy deals 50% less damage. Core for Doom builds. |
| Great | Book Repair Knife | Heal 3 HP on Doom kills. Offsets low HP pool. |
| Great | Energy relics | Necrobinder is energy-hungry. Any extra energy is high value. |
| Good | Draw relics | More cards = faster Doom/Soul cycling. Synergizes with lean decks. |
Upgrade Soul Spark first. Going from 6→9 damage + adding Vulnerable increases Act 1 elite kill rate dramatically. Never upgrade Defend early — Necrobinder survives by killing fast, not blocking.
Don't mix archetypes too early. Pure Doom and pure Osty builds both have clear power spikes. Hybrid decks usually do two things poorly instead of one thing well. Commit after Act 1 boss.
Osty damage absorption is slightly bugged. As of launch patch, damage sometimes leaks through when Osty should absorb it. Keep an eye on patch notes for fixes.
Scythe is the dream card. If you find this rare card in early Act 1, build around it. By Act 3, a single Scythe swing can deal 100+ damage. Feed it every fight.
Play one run as the Regent first. Unlock chain: Ironclad → Silent → Regent → Necrobinder.
Yes, via Prismatic Shard. Ironclad Exhaust cards and Silent discard synergies work exceptionally well with Necrobinder mechanics.
Excellent. She provides massive damage while teammates handle defense. Necrobinder + Ironclad + Defect is currently the community-favorite 3-player comp.
This guide synthesizes strategy discussion from r/slaythespire, the official STS2 Discord #strategy channel, Mobalytics character guides, and early-Ascension community data. Build ratings reflect Day 4 consensus and will shift as the Early Access meta evolves.