Here is the full list of all 13 Seventh Lair achievements.
Finished reading the short story
To each their own path
Exposed the truth of Seventh Lair
Arrived in Fairy House
Learn the identity of a certain someone
Returned peace to the world... or did you?
Learn the identity of The Dutch Decapitator
Finish 'The Life of a Creator iii'
Destroyed the Demon
Finish 'The Life of a Creator II'
Get a new friend in the Starting Village
Finish 'The Life of a Creator I'
You've been thrown into a new journey