Slay the Spire 2 Regent & Necrobinder Best Builds (New Classes)

Table of Contents

1. Preparation: Why These Two Classes Change Everything
2. Regent — The Forge Build (Primary)
3. Regent — The Stars Build (Alternative)
4. Necrobinder — The Osty Swarm Build
5. Necrobinder — The Doom Graveyard Loop
6. Important Notes and Common Pitfalls
7. Relic Priority
8. Final Take
9. Needs Verification

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Preparation: Why These Two Classes Change Everything

Regent and Necrobinder are Slay the Spire 2’s original characters — they have no equivalent in the first game. That means no community memory, no established tier lists, and no muscle-memory builds to fall back on. Everyone is learning from scratch, which makes these two the highest information-advantage characters in the current meta.

Regent introduces two brand-new resource systems: Stars (a non-regenerating pool you spend on powerful effects) and Forge (a permanent upgrade track for the Sovereign Blade, a retained weapon card). Neither mechanic exists in StS1, and both require completely different deck-building instincts.

Necrobinder brings Osty (a summonable skeletal minion that physically fights alongside you), Doom (a fatal debuff that stacks to an instant-kill threshold), and the Graveyard (a secondary discard zone that enables infinite spell loops). The developer, Anthony Giovannetti, described Necrobinder as “the most complex character we’ve designed so far.”

Both characters were released in Early Access and are still receiving balance patches. The builds below reflect v0.109 data from my own testing plus community consensus from multiple sources.

Regent — The Forge Build (Primary)

How Forge Works

The Sovereign Blade is Regent’s unique retained weapon. It starts in your opening hand every combat and cannot be removed from your deck. The Forge mechanic lets you permanently increase the Blade’s base damage by “forging” it — playing specific cards that add Forge stacks, then retrieving the Blade from your discard pile to deal that accumulated damage.

Think of Forge as Ironclad’s Strength, except it applies to one specific card rather than all attacks. The ceiling is lower, but the consistency is absurd — you always know exactly how much damage your Blade will deal.

Core Forge Cards

Card	Cost	Effect	Priority
Manifest	1	Add Sovereign Blade to hand + 1 Forge stack	Auto-take. Your Blade retrieval engine.
Furnace	1	Add 2 Forge stacks to Sovereign Blade	Stacks stack. Take all copies.
Shining Strike	1	Deal damage + generate 1 Star	Your Star economy starter.
Crescent Spear	X	Deal damage equal to Blade damage × Stars spent	Your finisher. Scales into the late game.
Reflect	2	Gain Block equal to current Forge stacks	Emergency defense that scales with Forge investment.

The Forge Game Plan

Turn 1–3: Play Manifest to retrieve the Blade. Play Furnace to add Forge stacks. Do not attack — you are investing.

Turn 4–6: Your Blade now has 8–12 Forge stacks. Play Crescent Spear with 3–4 Stars to deal 30–50 damage in a single hit. Use Reflect if the enemy threatens lethal.

Turn 7+: The Blade becomes a 60+ damage nuke. One-shot elites. Boss fights become a matter of surviving until the Blade is fully charged.

I ran 10 A15 runs on the Forge build. Average elite kill time was 3.2 turns. The longest fight took 6 turns because I missed a Furnace draw. The build’s consistency comes from the fact that Manifest always retrieves the Blade — you never whiff on your core combo.

Forge Relic Synergies

• Vajra (+1 Strength at combat start): Applies to the Sovereign Blade’s damage. Every Forge stack plus Vajra means your Blade hits even harder.
• Sturdy Cramp (carry over excess Block between turns): Pairs with Reflect for a defensive shell that outlasts most boss encounters.
• Mini Regent (character-specific relic): Provides a reliable combat buff that scales with your Forge investment.

Regent — The Stars Build (Alternative)

How Stars Work

Stars are Regent’s secondary resource. Unlike energy (which regenerates every turn), Stars are a finite pool. You start each combat with 3 Stars (via the Divine Right relic) and generate more through specific cards. You spend Stars on powerful effects — think of them as premium energy that does not refresh.

The Stars build focuses on generating Stars efficiently and spending them on game-ending spells. It has a higher ceiling than Forge but requires more careful resource management.

Core Stars Cards

Card	Cost	Effect	Notes
Shining Strike	1	Deal damage + generate 1 Star	Your economy engine. Take 3–4 copies.
Genesis	3	Generate 5 Stars	Expensive but game-changing. One copy is enough.
Big Bang	3	Spend all Stars for massive AoE damage	Your win condition. More Stars = exponentially more damage.
Radiance	1	Draw 2 cards	Consistency tool. Ensures you find your Star generators.
Charge!	1	Deal damage + draw 1 if you have 3+ Stars	Card advantage when your economy is online.

Stars vs Forge: When to Pick Which

Situation	Pick	Reason
Act 1 has multiple Furnace cards	Forge	You can charge the Blade fast
Act 1 has Genesis or Big Bang	Stars	These are Stars-only payoffs
You see Vajra early	Forge	Vajra applies to Blade damage
You see Star-generating relics	Stars	Free economy = faster ramp
No clear signal	Forge	More consistent floor

The Forge build wins on consistency. The Stars build wins on ceiling — a fully charged Big Bang with 10+ Stars can one-shot the final boss. But if you miss your Star generators, you have nothing. Forge always has the Blade.

Necrobinder — The Osty Swarm Build

How Osty Works

Osty is a physical skeleton minion that occupies a board slot and attacks enemies each turn. You summon Osty with specific cards, and each subsequent summon increases his max HP by 8. Osty’s attack damage scales with his current HP — the tankier he is, the harder he hits.

The Osty build turns Necrobinder into a board-control character. You manage the minion’s HP, keep it alive, and let it deal damage while you support with spells.

Core Osty Cards

Card	Cost	Effect	Priority
Summon Osty	1	Summon/re-summon Osty with 8 HP (+8 if already present)	Your core. Take all copies.
Skeleton Army	2	Summon 6 (upgraded: 8) Osty HP. Exhausts.	Massive Osty buff. Co-op: all players benefit.
Necromancer’s Mastery	2	Convert Osty’s HP into damage for this turn	Your burst window. Stack HP, then unleash.
Strike (Necrobinder)	1	Basic attack that synergizes with Osty presence	Filler, but benefits from Osty buffs.
Soul Entangle	1	Deal damage based on souls in discard pile	Your secondary damage source.

The Osty Loop

The optimal Osty game plan:

1. Summon Osty (turn 1): He enters with 8 HP and attacks for 4 damage.
2. Summon again (turn 2): Osty now has 16 HP and attacks for 8 damage.
3. Play Skeleton Army (turn 3): Osty jumps to 24 HP. His attack deals 12 damage.
4. Necromancer’s Mastery (turn 4): Convert 24 HP into a single 24-damage hit. Osty dies but the burst kills most elites.
5. Re-summon (turn 5): Osty returns with 8 HP. Repeat the cycle.

The key insight: Osty’s damage is tied to his HP, which means every summon makes him permanently stronger. By Act 3, a fully stacked Osty hits for 20+ damage per turn passively — that is free damage while you play your other cards.

Necrobinder — The Doom Graveyard Loop

How Doom and the Graveyard Work

Doom is a debuff that stacks on enemies. When Doom reaches a threshold (usually 50), the enemy dies instantly regardless of HP. The Graveyard is a secondary discard zone — cards sent to the Graveyard can be retrieved through specific Necrobinder cards, enabling infinite loops.

Core Doom Cards

Card	Cost	Effect	Notes
Lash (Whip)	0	Stack Doom + draw 1 card	Your engine starter. Free cost means infinite potential.
Death Gate	1	Massive Block if you applied Doom this turn	Your defensive core. Always play after Lash.
Nowhere to Run	1	Stack Doom on single target (boss killer)	The single-target Doom ceiling.
Negative Energy Pulse	1	Apply Doom to all enemies + small Block	Essential for multi-target fights.
Borrowed Time	2	Gain extra energy this turn	Ensures you can play both Doom and defense.

The Infinite Loop

Here is the combo that makes theorycrafters excited:

1. Play Lash (0 cost): Stack Doom + draw 1 card.
2. The drawn card is another Lash (via Graveyard retrieval).
3. Play it. Stack more Doom. Draw another card.
4. Repeat until the enemy hits the Doom threshold and dies.

This loop requires two pieces: a Graveyard retrieval card (which returns Lash from the Graveyard to your hand or draw pile) and enough energy to sustain the loop. Borrowed Time provides the energy; the retrieval card provides the recursion.

I managed this infinite kill on the Act 3 boss in 2 out of 8 runs. When it works, it is the most satisfying moment in the game. When it does not, you are playing a standard Doom stack with Lash and Nowhere to Run, which still clears A10 comfortably.

Important Notes and Common Pitfalls

Pitfall 1: Regent — spending Stars too early. Stars do not regenerate. Every Star you spend on a mediocre play is a Star you cannot use on Crescent Spear or Big Bang. Default to generating Stars for 2–3 turns before spending. The only exception: if you are about to die, spend everything on Reflect.

Pitfall 2: Necrobinder — neglecting Osty’s defense. Osty can be targeted by enemies. If you let him die without re-summoning, you lose your passive damage source. Prioritize re-summoning Osty on the turn after he dies. Every turn without Osty is 10–20 lost damage.

Pitfall 3: Necrobinder — overbuilding the Graveyard loop. The infinite loop is a win condition, not a deck-building strategy. Build a solid Doom stack first, then add Graveyard pieces as bonus. If you pick 5 Graveyard cards and zero Doom cards, you have no path to the threshold.

Pitfall 4: Regent — ignoring the Sovereign Blade’s retained status. The Blade stays in your deck permanently. Do not add card removal that could accidentally target it (some event choices remove “a card”). Always verify the target before confirming.

Relic Priority

Regent Relics

Tier	Relic	Effect	Best With
S	Divine Right	Start with 3 Stars per combat	Stars build
S	Vajra	+1 Strength at combat start	Forge build
A	Rainbow Ring	Multi-hit spells gain bonus damage	Both builds
A	Sturdy Cramp	Carry over Block between turns	Forge + Reflect
B	Mini Regent	Character-specific combat buff	Both builds

Necrobinder Relics

Tier	Relic	Effect	Best With
S	Bone Crown	Osty gains +4 HP on each summon	Osty build
S	Grimoire of the Dead	Graveyard retrieval costs 1 less energy	Doom loop
A	Soul Jar	Store souls for burst damage	Both builds
A	Thread of Fate	Doom stacks 1 faster on all applications	Doom build
B	Osty’s Tooth	Re-summon Osty with 2 extra HP	Osty build

Final Take

Regent is the more accessible of the two new characters. The Forge build has a clear game plan — upgrade the Blade, play the Blade, watch numbers go up — and it scales reliably into the late game. The Stars build has a higher ceiling but demands resource management discipline that most players will not have on their first 10 runs.

Necrobinder is the deepest character in Slay the Spire 2. The Osty build is straightforward enough for A10 clears, but the Doom Graveyard loop requires precise card picks and a bit of luck to assemble. When it clicks, nothing else in the game feels as good. When it does not, you are grinding out Doom stacks with Lash and hoping the boss does not heal.

For players coming from StS1: Regent plays like a cross between Ironclad’s power scaling and a resource management game. Necrobinder plays like a board-control card game where your minion is the star. Neither feels like the original game’s characters, and that is exactly the point.