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