Evil omens possess an instinct similar to that of wild beasts, a fact well known to Feng Xue, and beyond instinct, they also have certain tendencies based on their "type."
These tendencies are somewhat akin to the corrupt gods poisoned by faith in novels read before traversing, simply put, "What they are rumored to be, they become."
For instance, if undead creatures are universally believed to loathe the living, then undead omens will show intense hostility toward living people; similarly, if giant dragons are thought to covet treasures, then dragon omens will take valuable items they see back to their nests, even though they can't understand the true worth of these items.
However, playing dead is different because it involves "proactivity" and "choice."
Although dragon omens will take treasures they encounter back to their lairs, they do not actively seek out treasures as if hunting, which reflects whether they are proactive.