Here is the full list of all 27 Dungeons - there are The Dark Lord achievements.
Let the skeleton fall into the well.
Vanquish the yeti.
Escape the Noseghul.
Complete all tutorials.
Survive 60 minutes in any survival map.
Accumulate 5,000 prestige in any “sandbox” map.
Kill 12 heroes at once using Calypso's Roundhouse Kick.
Kill 6 heroes at once using Calypso's Roundhouse Kick.
Kill 3 heroes at once using Calypso's Roundhouse Kick.
Win any multiplayer “Piñata” map.
Collect a total of 50,000 prestige in multiplayer “Piñata” matches, across all playthroughs.
Collect a total of 5,000 prestige in multiplayer “Piñata” matches, across all playthroughs.
Win any multiplayer “King of the Hill” game as the Zombie King.
Win any multiplayer “King of the Hill” game as Minos.
Win any multiplayer “King of the Hill” game as the Dark Lord.
Win any multiplayer “King of the Hill” game as Calypso.
Use 50 scrolls.
Use 10 scrolls.
Drink 50 potions.
Drink 10 potions.
Achieve a monster level of 20 in any map.
Learn more about the Zombie King.
Summon the army of the living dead.
Lift the siege of Marthas' Deep.
Encounter the beast in the grottoes.
And so is the last of our budget…
Kill the giant spider.