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