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