The ecology of the depths changed dramatically once creatures reached Gold Rank. It was like crossing an invisible line where all previous rules of the underground ecosystem were completely rewritten.
The lesser Deep Terrors that Ren had been seeking still behaved in some ways like the Deep Killers they evolved from: aggressive, territorial, dependent on quick ambushes and paralyzing surprise attacks. But when they reached Gold, their strategy evolved toward something much more sophisticated and passive.
They no longer had the natural evolutionary advantage of being fast predators with superior abilities.
