Downfall is a fan-made expansion mod for Slay the Spire, built around an alternate campaign in which players take the roles of the Spire’s villains. It adds seven villain characters with individual card pools, relics, potions, and distinctive mechanics, while also introducing the Hermit as a new hero for the standard side of the game. The alternate mode turns the climb on its head: villains travel down the Spire and defend its Heart from the familiar heroes.
The characters distinguish themselves through specific systems rather than simply changing their card selections. The Hermit’s Dead On cards gain bonuses when positioned in the middle of the hand, making the order in which other cards are played or exhausted matter. The Guardian collects Gem cards and sockets them into other cards to customize their effects, while the Hexaghost uses Ghostflame to ignite surrounding fires for extra damage and other bonuses. These character-focused mechanics give deck-building and combat different strategic textures.
Downfall also adds material that reaches beyond its alternate campaign. Villain relics and potions can enter the standard pool, alongside boss-themed cards, events, curses, and modifiers for Daily and Custom runs. The villains can also be enabled for standard play through the configuration menu. Its combination of a reversed campaign, new playable identities, and additions to the original run structure makes this mod a broad reworking of Slay the Spire rather than a single-character add-on. The mod’s content may differ from the base game’s usual experience.
