Here is the full list of all 67 Crystal Maidens achievements.
Upgrade a building up to level 10
Upgrade 30 legendary items to the level 5
Lose 500 battles
Play 500 battles with Engineer class
Play 500 battles with Marksman class
Find 10 legendary items in the Campaign Mode
Upgrade 10 legendary items to the level 5"
Find 5 legendary items in the Campaign Mode
Upgrade 1 legendary item to the level 5
Upgrade 30 epic items to the level 5
Play 100 battles with Engineer class
Play 15 days in a row
Upgrade 10 epic items to the level 5
Play 50 battles with Engineer class
Upgrade a skill to the level 20
Romance 15 maidens to level 3
Upgrade 1 epic item to the level 5
Play 100 battles with Marksman class
Play 500 battles with Support class
Upgrade 30 rare items to the level 5
Play 50 battles with Marksman class
Lose 100 battles
Earn 1 million coins in Campaign Mode
Play 100 battles with Warrior class
Earn 180 stars in Campaign 1
Lose 50 battles
Get a hero up to level 60
Play 500 battles with Mage class
Find a legendary item in the Campaign Mode
Play 7 days in a row
Upgrade 10 rare items to the level 5
Romance 5 maidens to level 3
Earn 250.000 coins in Campaign Mode
Upgrade 30 common items to the level 5
Win 50 battles with all 3 stars
Complete level 60 of Campaign Mode
Upgrade a building up to level 5
Own 10 maidens
Own 15 maidens
Kill 1000 enemies in battle
Play 100 battles with Support class
Win 20 battles with all 3 stars
Upgrade 10 common items to the level 5
Play 100 battles with Mage class
Get a hero up to level 30
Earn 120 stars in Campaign 1
Upgrade 1 rare item to the level 5
Play 50 battles with Support class
Play 50 battles with Mage class
Kill 250 enemies in battle
Upgrade a skill to the level 5
Complete level 30 of Campaign Mode
Upgrade a building up to level 2
Earn 60 stars in Campaign 1
Upgrade 1 common item to the level 5
Play 50 battles with Warrior class
Kill 100 enemies in battle
Romance 2 maidens to level 3
Earn 5000 coins in Campaign Mode
Own 5 maidens
Get a hero up to level 10
Win 5 battles with all 3 stars
Complete 10 quests
Complete 50 quests
Complete 200 quests
Complete level 1 of Campaign Mode