Choose Inlaid Library and your favourite character, just make sure to check off inverse at the bottom before starting. It’s self explanatory but a couple of notes.
-You can quit as soon as you hit level 80, no need to finish the level.
-The achievement may be very delayed or require a restart of the game. Upon completion for me it showed the achievement box in game but nothing popped. Once I restarted and pressed start, the achievement popped.