Demon Evolution Concept-Stitch

Here's an evolutionary chart of my demon mythology.

Example: Stitcher-
Stage 1.) Human soul departs body and resembles original body.

Stage 2.) Human soul enters hell and is tortured and ravaged. Soul integrity begins to deteriorate and soul starts to show signs of aggression and fear.

Stage 3.) Human soul is no longer recognizable and appears as a smoke-like entity. Demon is born. Body is ethereal and can easily pass through obstacles. Appearance uniform. Standard abilities include possession, telekinesis, telepathy, etc.

Stage 4.) After creation, a demon searches for other demons/tortured souls to consume. After enough demons/tortured souls have been consumed body begins to solidify, yet still retains smoke-like properties. Demon becomes more aggressive and powerful. Appearance starts to vary and individualize. Abilities, however, still similar to stage 3. Link to an example of a Stage 4 Demon: [link]

Stage 5.) Body begins to completely solidify and appearance is greatly individualized from other demons. Resembles more of a creature than smoke. Demon also begins to manifest abilities unique to itself. Abilities present in earlier stages, however, generally begin to dissipate. Intelligence increases to a more-than-instinctual desire to consume. Curiosity is also observed in the creature's behavior in this stage.

Stage 6.) Demon is viewed as an individual and does not resemble others of its kind. Begins to show human level intelligence, and displays an extreme amount of curiosity in its surroundings. Quite particular about the prey it hunts though, and seems to search for 'worthy' opponents to kill. Links to examples of a Stage 6 Demon:
[link]
[link]

Stage 7.) Body almost completely resembles a humanoid figure. Some of Stage 6 abilities and body marks, however, are displayed upon the body of the demon. Cocoon-like metamorphosis is thought to contribute to a dramatic change in the demon's appearance. Able to blend into a crowd of humans almost completely undetected to approach desired prey. Intelligence is on-par with a 10-14 year-old child and learns from mistakes. Displays extreme caution when against opponents, and plans its attacks based on the opponents' weaknesses.
Link to an example of a Stage 7 Demon: [link]