Potions
Potions can be brewed in your Alchemy Lab. From there, a potion can be picked up and then dropped on your own territory to release the effect. Do not overlook the usefulness of potions.
Availability
You normally don't start with any potions available and have to unlock them in the Veins of Evil. But the campaigns often deviate from this, usually letting you start a level with access to all previously unlocked potions.
Haste
Cost: 750 gold
Increases the movement speed of your minions in a small area for 45 seconds. Enemies caught in the area will be slowed down. The effect decays over time.
Transmutation
Cost: 1500 gold
Conjures a 3x3 zone of transmutation which adds Fool's Gold to blocks, converts dead minions into golden statues, and damages enemies caught inside. The damage is significantly increased against minions made of gold. Fool's Gold cannot be absorbed by the Aureate Monolith or Colossus.
Work-A-Lot
Cost: 1500 gold
Minions caught within the effect of this potion enter a trance-like state which allows them to work significantly faster for 10 seconds.
The effect of this potion is really good so definitely don't overlook it. You can drastically increase the speed that work is being done.
Quick Freeze
Cost: 1500 gold
Freezes a 3x3 area completely solid for a short time, freezing and disabling all minions and tiles including your own, and instantly killing Ember Demons. Everything affected remains invulnerable for the duration.
Useful for temporarily keeping an attacking force at bay.
Spirit Workers
Cost: 1500 gold
Spawns 5 temporary Spirit Workers which dig out the dungeon and don't have any needs to fulfil. They also move and work much faster than regular Workers and are impervious to attack; but they cannot unclaim enemy tiles or dig out their walls. Spirit Workers summoned from potions only have a short lifespan.
This potion is one of the most powerful potions you can brew. Spirit Workers can dig and claim territory so fast that it can give you a significant advantage. Since the Spirit Workers are impervious to damage, they can also prevent enemies from claiming rooms or shrines no matter how big the attack.
Reanimation
Cost: 1500 gold
Creates Banshees from prisoners, souls (from the Crypt or Well of Souls), and dead or unconscious units. Banshees hone in on the nearest enemy Dungeon Core, Core Shard or Underhill. They detonate as soon as they encounter an obstacle or are slapped, dealing more damage the more health they have left.
Frost Weaver
Cost: 2000 gold
Summons a sturdy Frost Weaver to defend the area where it is spawned, but it will gradually melt away over time. It will freeze nearby enemies to dramatically reduce their movement and attack speeds. Frost Weavers don't collect pay or have any needs to fulfil. Won't respond to Rally flags.
Keeping one or two of this potion in your Alchemy Lab is not a bad idea as they can be used to quickly defend against an unexpected attack. While the Frost Weaver keep the enemy occupied, you get the time you need to ready a proper defense.
Hellfire
Cost: 2500 gold
Explodes in a 3x3 area, dealing 300 damage to all blocks and damaging enemies.
Wisdom Juice
Cost: 4500 gold
Shares a generous splash of distilled experience between all minions caught in the blast.
This potion can be helpful in leveling up some minions quicker, especially while they are still at lower levels.
Wormhole
Cost: 7500 gold
Opens a vortex which lasts for 5 seconds, teleporting all units friend or foe back to your Dungeon Core. But the violent forces will destroy all walls around your Core.
Thunderling
Cost: 12500 gold
Summons a Thunderling, a powerful elemental demon which heavily damages and stuns nearby enemies. Thunderlings don't train or have any needs, and can be rallied separately to other minions. Slap 3 times to dismiss. Locks 250 mana.