HITMAN 3, A Murder By Proxy, Domestic Disturbance and Scandal! Challenges in Mendoza, THE FAREWELL mission.
All of these challenges will be done during the playthrough. You can unlock A Proxy Killer by using a Mercenary to shoot Tamara Vidal with a Sniper Rifle and make Valentina Yates push Don Yates over a railing. First, you can take care of Don and Valentina Yates to complete the SCANDAL and Domestic Disturbance challenges. Two Mercenaries near the doors to the garden will talk about a safe and a code, they will mention the date of Valentina and Don’s marriage as the code to the safe.
In the bedroom, you might get a calendar. Intel will mention a crystal wedding anniversary (the game takes place in 2021, a crystal anniversary means that marriage took place in 2006). Enter 2006 as the code to the safe and you’ll get a file. Give these files to Valentina and then all you have to do is just wait for the job to be done.
Then you can just complete a Mission Story with a Sniper against Vidal. Grab a Gaucho disguise, take an earpiece, scan Tamara Vidal, and wait until the Sniper has a clear shot. Once Tamara can be seen by a Sniper, order a shot and the challenge will be done once both targets are eliminated.
