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