Necrobinder

The Necrobinder is a sardonic lich spellcaster and one of the two new playable characters introduced in Slay the Spire 2. With notably low starting HP and the starting relic Bound Phylactery that summons 1 creature at the start of each turn, the Necrobinder is the most mechanically complex character in the game, featuring three interlocking systems: Osty, Doom, and Souls.

Osty is a giant reanimated skeletal hand that serves as the Necrobinder's companion in every combat. Osty has its own HP pool that absorbs incoming damage before it reaches the Necrobinder, functioning as a living shield. Cards with the Summon keyword either revive Osty or add HP to a living Osty, while attack cards like Poke, Flatten, and Rattle command Osty to deal damage. The rare card Sacrifice can convert Osty's entire HP pool into Block, creating dramatic defensive plays in critical moments.

Doom is a unique debuff that acts as a death mark. When an enemy's HP falls to or below their Doom stacks, they are instantly executed regardless of Block or other defenses. Cards like Blight Strike, Death March, and End of Days apply Doom, while Reaper Form makes all your Attacks also apply Doom equal to their damage. The Doom archetype excels against high-HP bosses like Kaiser Crab, whose massive Block stacks are completely irrelevant when Doom triggers the execution.

Souls are powerful cards that cost HP instead of Energy, going to the Graveyard instead of the discard pile when played. Graveyard retrieval cards like Dredge and Seance pull cards back for reuse, creating a loop of devastating spells. Key Soul synergies include Haunt, which damages enemies when Souls are played, and Devour Life, which summons Osty when Souls are played. The Necrobinder rewards mastery of all three systems, as the strongest runs weave Osty tanking, Doom execution, and Soul recursion into a single devastating strategy. Against bosses like Doormaker and Test Subject #C10, a fully realized Necrobinder build is among the most powerful strategies in Slay the Spire 2.