Die by the Sword
How to unlock: You need to complete mission World of Tomorrow in Sapienza
Comment: You will unlock the achievement, regardless of the methods you choose to assassinate Silvio Caruso and Francesca de Santis.
Not in the Guidebook
Way to unlock: Complete all Opportunities in World of Tomorrow during the mission in Sapienza.
Comment: Use all the opportunities to eliminate your targets. You can go through their list by pausing your game and selecting the right tab. It is obvious that you cannot complete all of them in a single gameplay. You need to play Sapienza several times and each time you should focus on one specific opportunity (maybe two if they are related to different targets and do not exclude one another). Tips on how to eliminate main targets were presented in the walkthrough.
How to unlock: Complete the fifth level of escalation in Sapienza.
Comment: With each escalation, Agent 47 will face more and more complex challenges related to assassinations. Sapienza offers several escalations, and in order to unlock this achievement, you need to complete one of them.
How to unlock: You need to select an alternative starting point in Sapienza and use the Agency to help you smuggle something to the area.
Comment: Both options will become available once you reach higher ranks. Try to complete Sapienza mission on "regular rules" at least once, before you decide to choose the starting point and use equipment delivery.
Way to unlock: Reach Sapienza Mastery Level 20.
Commentary: Finish the challenges connected to the mission. Eliminate the targets in different ways, acquire different items and use different paths of evacuation. You do not have to finish all of the challenges to get the highest rank. Focus on those you want to finish firstly.
Awakened the Kraken!
One of the two secret achievement in Sapienza mission.
Way to unlock: Shoot the bells on the boat with a sniper rifle.
Commentary: Get the sniper rifle and shoot the bells from the roof of the mansion. You will have to shoot four bells to unlock this achievement.
The Sapienza Trinity
Another secret achievement from Sapienza.
Way to unlock: This achievement requires you to assassinate Silvio Caruso in three unique ways; by killing him during a therapy session as his Doctor, by shooting his plane with cannon as he escapes and by sniping him through the lens of a telescope as he looks through it. These assassinations can be quiet.
Commentary: In order to destroy the plane, force Silvio to escape an head to the courtyard with the cannons (M4,43). Load the cannon ball, fill the gun with the powder, and wait for the plane to get in the way. As for the last way: Equip yourself with a sniper rifle. Press a button for the dome of the observatory to make the telescope appear (M4,12). Silvio will come there soon. Go to the top of the tower with your rifle which will be waiting for you on its ground level (M4,57). Wait for Silvio to look through the lens and shoot him.