Slay the Spire 2 Necrobinder guide: Osty and Doom

This Slay the Spire 2 Necrobinder guide starts with a useful Osty and enough immediate damage and defense to survive the first cycle. Treat Doom as a delayed finish, and check what happens before that finish arrives.

Osty’s current HP matters

The checked Main reference lists Bound Phylactery summoning 1 at the start of your turn. Its starting deck includes Bodyguard and Unleash. The separate Main guide lists base Bodyguard as a 1-Energy Summon 5 card, and Unleash as damage based on 6 plus Osty’s current HP.

Those are Single source numerical references for this draft, not in-game measurements. The route advice also distinguishes current HP from maximum HP: a recently damaged Osty may have a large ceiling and still give a weak current-HP attack.

A turn-order example

If you plan to use an ordinary Osty attack and then a card that spends or kills him, inspect both texts before reversing the order. Hizzle recommends checking whether the damage depends on his current state and whether you can rebuild protection before the enemy attacks.

Osty does not replace every form of defense. The checked reference describes him absorbing Attack damage after Block; direct health loss and other effects need their own answers. Do not count his health as universal immunity.

Doom is not an immediate safety switch

The checked rule executes an enemy at the end of its turn when Doom reaches at least its current HP. That enemy can still act before the ordinary execution. Keep enough defense to survive that action, or use a separately supported effect that changes the timing.

Souls and Ethereal packages offer other directions, but an unsupported payoff is still a slow card. UNSURE: complete advanced routes and all interaction exceptions. Main Sacrifice’s published double-max-HP Block value is not Beta’s triple value; read the version before borrowing a showcase.

Related: Slay the Spire 2 beginner guide: first run, Slay the Spire 2 Ironclad build: early plan, Slay the Spire 2 achievements: current status, Slay the Spire 2 patch notes: Main versus Beta, Slay the Spire 2 Regent guide: Stars and Forge, Slay the Spire 2 how to unlock all characters, Slay the Spire 2 how to play the beta branch.