Your Slay the Spire deck is Hearthstone minions now.
Slay the Hearth turns a full Slay the Spire run into a Hearthstone minion brawl. Every class plays its Hearthstone counterpart, and Act 1's enemies, elites and bosses are Hearthstone minions too.
How it plays
Minions are your cards. Playing a minion deals its Attack as damage, gives its Health as Block, and fires its keyword: Battlecry, Deathrattle, Taunt, Divine Shield, Charge, Stealth, Poisonous, Combo, Freeze and Spell Damage, each translated into Slay the Spire terms.
Four class pools. Ironclad gets Warrior minions (Armorsmith, Frothing Berserker, Grommash), Silent gets Rogue (SI:7 Agent, Edwin VanCleef, Patient Assassin), Defect gets Mage (Water Elemental, Kirin Tor Mage, Antonidas, who channel orbs) and Watcher gets Priest (Northshire Cleric, Auchenai, Velen, who use stances). Shared neutrals include Chillwind Yeti, Knife Juggler, Sylvanas, Cairne and Leeroy Jenkins.
Hearthstone power levels kept. Mana cost maps to energy and stats map to damage and Block, so a Boulderfist Ogre hits like one and Leeroy is cheap burst with a drawback.
Act 1 is a Hearthstone board. Murloc packs, Leper Gnomes that hit you when they die, a Harvest Golem that comes back as a Damaged Golem, elites Grommash Hellscream, Sylvanas Windrunner and the Argent Crusade, and one of three bosses: Ragnaros the Firelord, Onyxia (with whelps) or Ysera.
Requirements
Slay the Spire and Hearthstone, both installed. Single player.
Card names and art come from your own Hearthstone install when the game starts, in your game's language, and are cached in %LOCALAPPDATA%\Hearthspire. Nothing from Hearthstone is in the download. The Hearthstone client is never started or modified, so your Blizzard account isn't touched.
Acts 2 and 3 are vanilla for now.
Credits
ModTheSpire by kiooeht and BaseMod by t-larson and contributors (both MIT, bundled unmodified)
Unity type-tree string table from UnityPy (MIT)
Hearthstone (c) Blizzard Entertainment and Slay the Spire (c) Mega Crit. This is an unofficial fan mod.