As the devorator had to swim constantly to survive, ultimately traits which supported this were very strongly selected for over these millions of years. The Mailclad Devorator replaced its ancestor and vastly streamlined its shape to use as little energy as possible while swimming. Among other things, this meant smoothing out its armor; to do this without losing the benefit of the protection of the spikes in fights with others, it has simply developed more rings of armor, which completely cover most of its body. Genetically, these are segmented, though the rest of the body still isn't. Its tail fin is now lunate in shape, the only option it has for efficient non-stop swimming, and its dorsal fin is also greatly enlarged. A bit of armor extends over each of its fins without completely enveloping them, allowing it to have both protection and flexibility. Armor stretches down its tentacles as well, which are now wrapped around one another to create a more pointed, streamlined shape when not in use. Despite the increased armor coverage, it is actually more flexible than its ancestor, as the armor rings are not completely rigid and it is still able to wave its body back and forth as allowed by the gaps between them anyway.
The Mailclad Devorator has also developed slight hooks at the ends of its tentacles, used for grasping prey. Its eyes have advanced into complete camera eyes with flexible lenses, allowing it to see and focus on its surroundings with much more precision. Internally, it is much like its ancestor, including having 3 notochords.
The Mailclad Devorator is otherwise much like its ancestor. It crushes its prey using its tentacles when feeding, and it is always searching for more as meals can be infrequent in the abyss. It mainly hunts armored prey which cannot escape, as it isn’t particularly fast, though it will try to hunt other prey if it has the opportunity. It is able to identify the shape of its prey using its eyesight and illumination from its bioluminescent “UV bulbs” on the top and bottom of its head. It only meets others of its kind to fight or mate, and it has light purple blood.