This is my Halo 4 Promethean Watcher, or at least how it looks so far.
I customized the rings, made them articulated - you can move them and pose them however you want, and it's transparent so it's harder to see - much like the 'floating' parts on Didact and Knight.
They are done from only 1 ring, I separated it and didn't buy the second figure for second ring as in the game the watcher had only one ring that could have been separated into 2 parts.
This is how the Watcher looks so far, because I'm planning to do much more. I'll be repainting and touching the figure overall soon and later I plan to do a diorama for him and make him float there. Bigger diorama, because I also own Promethean Cralwer, Knight and Didact and I want my Watcher float somewhere behind them.
Please note, that the base I put the Watcher on is just temporarily until I'll finish a proper one.