[Render shot derectly in ZBrush]
At the end, I completed the challenge, except for parts A and B, the rest part were purely made by using brushes + Dynamesh.
Link of this Artwork: https://www.artstation.com/artwork/nY3e4K
Here is the link, It contained some Tech&Tips for sharing with you!
Tech & Tips sharing:
https://www.artstation.com/artwork/lxJbGO
Concept design: RenatusZ