r) "CREEP" - Stonekeep

Keep your imps under control by creating a small locked room for them and having only one excavate at a time to avoid them rushing out and taking tiles in front of patrolling heroes.

Use the Sight of Evil spell (a type of magic that reveals parts of the map) to watch for patrols and check upcoming rooms.

Take over the two workshops and create a couple of lairs and hatcheries.

Create a Secret Door (a type of door) just beyond the workshop doorways and lock it.

Carefully break down the other doors in the workshops, claim the tiles, and replace the wooden doors with locked Secret Doors. Locking a door prevents your imps and creatures from wandering into corridors and attracting attention.

To expand your fighting forces, excavate as far east as you can. You will find gold seams and three Salamanders near the lava.

Claim the prison with a goblin and the one with a Dark Mistress. If a guard spots you, pull your imps out using your Hand of Evil (a tool to move creatures).

Enlarge the prison by excavating more and sell the next room to place a small torture chamber inside.

To get more funds, excavate to the left and claim the library. Try to capture and convert the Wizard inside to research the new spell Create Gold, which allows you to sacrifice mana for gold.

Claim the prisons containing a Black Knight and a Warlock.

Begin incursions into the main body of the Keep. Take over central rooms but sell them off to increase cash and reduce areas needing defense.

Work your way east again from the last two prisons to find a graveyard. Sell the outside edges but keep the center bedrock to gain a Vampire.

Sell unneeded prisons to make space for a Casino and Combat Pit.

As you replace outer doors and claim interior rooms, you will encounter patrols. Keep Knights and Giants, and use the rest for Vampire food and skeleton fodder to bolster your forces.

Disable alarm traps as quickly as possible, ideally before patrols arrive.

Northwards, you will find two small guardrooms, each before two hero portals. Work your way through and disable all four portals.

Use Sight of Evil to locate Lord Pureheart in the central area.

Once your forces are trained, break through and let your imps claim territory. Drop all your minions into the area and defeat Lord Pureheart. Disabling the Hero Portals and killing his main patrolling force makes him an easier target.