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