Nick speaking,
I suppose it wouldn't be right if we didn't have a quick look at the two other Star Gods that remain for my New Necron Codex review, The Void Dragon and The Outsider!
There are implications that The Outsider is named so because it is physically outside of something, possibly the galaxy, and I cannot foresee the Outsider ever making it into the new Codex!
However..
We know that the Void Dragon may be on Mars, and that it may be feeding to return to strength! So there is a chance that it could make a HQ slot in the next Necron Codex. The Void Dragon is said to be the most powerful of the four remaining C'tan, so what sort of stats would it have?
It is said that The Void Dragon can control and consumes victims slowly through the use of technological implants and may be able to remotely control technology over vast distances, so it certainly has some interesting points that could be utilised. Maybe it could control your opponent's vehicles in some way? rolling on a chart for the result? A six and it's immobilised? On a personal note, I would love to have a C'tan that can move 12" or at least fleet, or both!
What rules do you think would be good for a new C'tan?