Here is the full list of all 18 Queen of Thieves achievements.
Romance Moirgane with Kira
Romance Fredrick with Thalia
Romance Tiberius with Joanne
Defeat Raul
Defeat Raul Demon
Romance Melvin with Thalia
Romance Melvin with Joanne
Romance Fredrick with Kira
Finish Game in Visual Novel Mode
Romance Mary-Ann with Kira
Romance Therjalla with Thalia
Romance Moirgane with Joanne
Earn 50.000 gold
Clear The Catacombs Of Undead
See Arianna in Sexy Outfit!
Romance Therjalla with Joanne
Romance Mary-Ann with Thalia
Romance Tiberius with Kira