Here is the full list of all 54 Fallen Enchantress: Legendary Heroes achievements.
Recruit Mausolos
Reach level 15 with a champion.
Win as Altar.
Win by casting the Spell of Making.
Win and have at least 3,000 population.
Win as Gilden.
Complete 10 quests in a single game.
Get a city to level 5 in one game.
Design a unit.
Play for 100 hours.
Not since Peter MacNicol has one been slain!
Defeat a faction.
You defeated a sovereign in battle!
Create a custom sovereign.
You have captured an enemy city!
Recruit Tuatha
Play for 40 hours.
Tap 10 resources in a single game.
Play for 20 hours.
Play for 10 hours.
Control 5 cities in a single game.
Play for 5 hours.
Reach level 5 with a champion.
Explore 10 goodie huts in a single game.
Buy an item from a shop.
You have defeated an army!
You killed a monster!
Your Fame has lead a hero to your cause.
Complete a quest.
All nations start with one.
You've managed to slay Abeix!
You've managed to slay Delin!
You've managed to slay Morian!
You've managed to slay Torax!
You've managed to slay Vetrar!
Awarded for completion of the Legendary Hero scenario.
Win by defeating all of your opponents.
Win by completing the Master Quest.
Win by forging an alliance with all players.
Win by having the highest score by the turn limit.
Win as Pariden.
Win as Tarth.
Win as Kraxis.
Win as Magnar.
Win as Resoln.
Win as Yithril.
Make 1000 gildar from selling items in shops.
Recruit Raza the Wild
Recruit Kasst
Recruit Gallowman
Recruit Nen Ratcatcher
Recruit Ascian
Win as Capitar.
Win as Umber.