Here is the full list of all 10 An Assassin in Orlandes achievements.
Find the best weapon
Find all the images in the book
Find the ultimate ending in Classic Mode
Roll 3 sixes in a single roll
Find Medius the Cannibal
Find the best armour
Find Eltane's castle
Find Kari
Roll 3 ones in a single roll
Find the ultimate ending in any mode