These two systems are listed together because building them separately turned out not to be an option.
Legible threat
An action thriller lives on the player being able to read what a threat is about to do. Tension comes from anticipating something, not from being surprised by it — surprise is a one-off, anticipation lasts the whole encounter.
So the AI had to telegraph. Enough wind-up on an attack to be readable, enough commitment that a read is rewarded.
Where destruction complicates it
Destructible environments mean the navigable space is not fixed. A route an enemy planned through is now rubble; cover the player was relying on isn’t there any more.
Naively, this produces enemies that path into walls that no longer exist, or stand in the open having lost the cover they were using. Both read as stupidity rather than as consequence.
Keeping navigation responsive to a level that’s being taken apart, without repathing so aggressively that enemies twitch, was most of the work — and the reason these ended up being one system rather than two.