Still playing and, until now, thoroughly enjoying Dishonored 2. It may have been an error in judgement, but I decided to do my first play-through as a no-kill, no-spot, collect all the runes and bonecharms run. Unfortunately I, and many others, have hit something of a wall in Chapter 5: The Royal Conservatory.
[Minor Spoilers Ahead] The Conservatory has been overrun with witches. To beat the area without deaths, you must activate a machine that eliminates the witches powers. This can incorrectly result in some of the unconscious witches dying.
Apparently this can sometimes be rectified by determining exactly which witches won’t walk again and putting sleep darts in them before activating the device. Unfortunately this did not work for me as can be seen in the following video:
In my case, activating the machine results in four dead witches. After a significant, time-consuming search, I determined which four were dying and collected them in the burglars apartment. In my case this group included the two would-be bushwhackers encountered outside of the Conservatory.
All four are resting comfortably on the floor and alive. Pull the switch and all four are dead. Reload and sleep dart the lot of them, then pull the switch. Now the statistics only show a single death, however examining the bodies directly show them all as dead.