Here is the full list of all 24 The Impregnation of the Elves: Conquest of the Arrogant Fairies by Impregnation achievements.
Achieved Ending 1
Unlock all achievements
Victory over Idun
Destroy Idun's armour completely
Achieved Ending 2
Defeated by Idun
Victory over Frigga
Destroy Frigga's armour completely
Defeated by Frigga
Victory over Nimue
Destroy Nimue's armour completely
Defeated by Nimue
Victory over Vivian
Defeated by Vivian
Destroy Vivian's armour completely
Victory over Nineve
Destroy Nineve's armour completely
Defeated by Nineve
See the Goddess' True Form
Victory over Dryad
Destroy Dryad's armour completely
Defeated by Dryad
Passed a question once
Defeat all the Elves in Challenge Mode