Full list of all 99 Crusaders of the Lost Idols achievements. It takes around 200 hours to unlock all of the achievements in the base game on Windows.
The base game contains 56 achievements, and there are 7 DLC packs containing 43 achievements.
Complete the 'Teacher's Pet' objective by beating area 500 in the 'Mischief at Mugwarts' campaign with some periodic polyfication.