Note: Killing Markus during your confrontation in ‘Crossroads’ will not unlock this trophy. It only counts during ‘Battle for Detroit’ but will not show up in the flowchart.
In order to achieve this trophy, you must have made Connor a deviant so that he is working side-by-side with Markus. Also make sure that Markus does not turn him away in ‘Night of the Soul’. For obvious reasons, both Markus and Connor must still be alive at this point in the story.
– Crossroads: when Connor confronts Markus, choose BECOME DEVIANT.
– Battle for Detroit: Markus must reach the end of his revolution; refer to the LIBERATION trophy.
– Battle for Detroit: have Connor convert the androids at the CyberLife tower; refer to the AN ARMY OF ME trophy.
– At the end, with Markus and Connor standing together, Amanda (Connor’s CyberLife connection) will try to hack Connor and force him to turn on Markus. At this point, do absolutely nothing – allow yourself to be hacked, and do not interact with the blue hand-icon touchpad! This will ensure that Connor kills Markus and you’ll achieve the trophy.