Summon
New in STS2Companion mechanics · Necrobinder
The Summon mechanic is central to the Necrobinder's identity. Osty — a giant reanimated hand — fights alongside you as a persistent companion. Buff Osty, command Osty, and sacrifice Osty for devastating effects.
How It Works
Osty the Companion
Osty is always present in Necrobinder combat. Osty has its own HP pool and acts at the end of each turn, dealing damage or blocking based on how you've buffed it.
Buffing Osty
Summon cards increase Osty's attack power, HP, or add special effects to Osty's end-of-turn action. Stacking Osty buffs is the primary Necrobinder scaling strategy.
Sacrifice
Sacrifice cards consume Osty's HP or destroy Osty entirely for massive one-time effects — huge damage, massive block, or powerful debuffs. After sacrifice, Osty can be re-summoned.
Re-summoning
If Osty is destroyed (by sacrifice or enemy damage), specific cards allow you to re-summon Osty. Re-summoned Osty starts fresh but can be buffed again.
Tips
- ▸Don't sacrifice Osty unless the payoff is worth it — losing Osty's passive damage is costly.
- ▸Prioritize Osty HP buffs early so Osty can absorb hits and protect your HP.
- ▸Sacrifice combos are strongest against bosses where the burst damage matters most.
- ▸In co-op, Osty's end-of-turn attacks contribute to Doom stacking on shared enemies.
Key Synergies
Osty's consistent end-of-turn attacks chip enemies toward the Doom threshold.
Reducing enemy Strength while Osty tanks hits is a strong defensive combo.
Sacrifice and Summon are two sides of the same mechanic — master both together.