Here is the full list of all 23 Legends of Aethereus achievements.
Build one statue
Build 10 statues
Complete one quest
Complete five quests
Finish the Obatymos quest line
Finish Alanas quest line
Complete the first level in Last Stand
Complete level 5 of Last Stand
Complete level 10 of Last Stand
Complete all levels of Last Stand
Complete the first level of Last Stand Extreme
Complete level 5 of Last Stand Extreme
Complete level 10 of Last Stand Extreme
Complete all levels of Last Stand Extreme
Craft one item
Craft an item with two stars
Die when playing a Hardcore Character at least of Level 15
Revive 15 Party Members
Reach 80 in the Attribute 'Intuition'
Complete level 5 of Last Stand Extreme in Hardcore Mode
Complete level 10 of Last Stand Extreme in Hardcore Mode
Complete level 15 of the Last Stand Extreme in Hardcore Mode
Complete all levels of The Last Stand Extreme in Hardcore Mode