Slay the Spire 2 Developer Interview — Designing the Necrobinder's Summon Kit

December 2025's PC Gaming Show: Most Wanted carried a Slay the Spire 2 developer interview that doubled as a design seminar on the game's hardest character: the Necrobinder, whose summon-and-sacrifice mechanics the team walked through in unusual depth.

The discussion covered the studio's design philosophy first — how the sequel evolves the original's deckbuilding core without losing the read-at-a-glance clarity that made it a classic — before zooming in on the lich. The Necrobinder, the team explained, was the game's high-difficulty expression: a character whose health pool is deliberately the smallest, and whose survivability is outsourced to Osty, the skeletal left hand she summons into every fight.

The mechanics on display:

• Summon stacking — Osty's health grows with every Summon effect, making him a rechargeable wall.
• Sacrifice payoffs — cards that kill Osty on purpose for immediate value, turning the summon into a reusable resource.
• The Bound Phylactery loop — Osty's automatic revival each turn, which makes death on your side of the board a schedule rather than a disaster.

For players, the interview's takeaway was a warning wrapped in an invitation: the Necrobinder was designed as the roster's deep end — complex, fragile, and enormously rewarding for players who think in resources rather than health bars. Our Necrobinder class guide and her four build routes are the practical companion to it.

Keep reading:

• Necrobinder Class Guide
• Soul Drain Engine Build