Here is the full list of all 35 Tower Behind the Moon achievements.
Ascend without flaw or compromise.
Ascend in any manner whatsoever.
Become an angel of the Dragon King.
Join the infernal hierarchy.
Claim the Kalyos Kalyonon, the Throne of Thrones, and rule the universe.
Become a magic book.
Ascend to join the archons.
Become a deity or celestial power.
Become a demon and carve out your own world.
Become a true lich.
Become a living continent.
Join the ranks of the immortals.
Reject ascension for love.
Reject ascension to try to protect the world.
Reject ascension to found a school of magic.
Reject ascension for conquest.
End your story with Heavy and Ruthless at 75 or higher.
End your story with Subtle and Inscrutable at 75 or higher.
End your story with Compassionate and Personable at 75 or higher.
End your story with Dynamic and Light at 75 or higher.
End your story with Ceremonial and Quick to Anger at 75 or higher.
Protect your tower from destruction.
Protect the town of Harpe from destruction.
End your story held in awe by your fellow magicians.
End your story beloved by the common people.
Shape-shift at least three times.
Fly at least three times.
Romance the angel.
Romance your apprentice.
Romance the bard.
Romance your castellan.
Romance the ruler of Harpe.
Name your monster.
Swordfight alongside a romantic partner.
Trap someone in Mynax's puzzle box.