Necro Mastery - Slay the Spire 2

Summon 5. Whenever Osty loses HP, ALL enemies lose that much HP as well.

TypePower

Cost2

RarityRare

Necro Mastery

+UPGRADED

Summon 8 . Whenever Osty loses HP, ALL enemies lose that much HP as well.

Spur1Skill
Retain . Summon 3. Osty heals 5 HP.
Summon synergy — Spur enables wide-board pressure and token advantage.
End of Days3Skill
Apply 29 Doom to ALL enemies. Kill enemies with at least as much Doom as HP.
AoE overlap — complements End of Days for multi-target encounter coverage.
Sacrifice1Skill
Retain . If Osty is alive, he dies and you gain Block equal to double his Max HP.
Shares the "hp-manipulation" mechanic with Sacrifice — core engine synergy.
Bone Shards1Attack
If Osty is alive, he deals 9 damage to ALL enemies and you gain 9 Block . Osty dies.
AoE overlap — complements Bone Shards for multi-target encounter coverage.