When do faceless transform?

[lumber-chick]

Just hit a seemingly random faceless situation. Dark VIP Liberation mission. Killed all aliens. On almost-last move of my last unit in a turn, which kills enemy unit, 3 faceless at medium-small distance from my squad activate.

They transform without being moved towards or attacked.

They did not transform upon gaining vision or when my soldiers moved to the same spots they are now last turn.

On alien turn, after transformation, they blue move and attack, killing a soldier.

Is it a feature or a bug?

Is there a reason not to kill all civilians in all cities now just because I can? (this is early April, no battle scanners or Specialist skills or anything)

[fowlJ]

You said you killed all the enemies on the map, so I'm assuming this is probably the vanilla faceless behaviour where unactivated faceless immediately become active when they are the only remaining enemies.

[hewhoispale]

Is there a reason not to kill all civilians in all cities now just because I can? (this is early April, no battle scanners or Specialist skills or anything)

Mechanically? Probably not. It would make XCOM the terrorist monsters ADVENT claims them to be though.

Besides the ethical questions, dark VIP missions tend to have a bunch of hidden faceless deployed. They are pretty rare outside of specific mission types or dark events.

[lumber-chick]

Thank you both for your answers.

Sounds like one can be more careful around civilians when fighting pods, take fewer risks and leave some actions unspent, and then get a bit more perspective beyond simply "it's unreasonable!".

Also the hint that killing all aliens triggers the transformation is a big one, didn't occur to me. I almost wish it simply didn't happen, but then again it is fairly predictable so can be countered through strategy. Maybe not so unresonable after all?

[chrisb]

Unknowns are unreasonable the first time they happen. Then you get revenge

[KevlinTallfellow]

When the very first move you make on a retaliation mission is Scanning Protocol to locate all the nearby "rebels"...