Great concept. ~Executed flawlessly. Has a real epic feel to it. Nice work buddy! Top row fo sho’
Thanks for the comments. Here’s a few of the ZBrush renders.
Basemesh made in Max.
Here are a few sample passes. I rendered a lot. 
And a few more renders. Basemesh, ZB renders etc. 
Beautiful!
very cool idea! 
a fantastic idea that is beautifully rendered 5 out of 5 in my book.
Very awesome idea, execution and final image!
Nice work on the sculpting. Im curious about your workflow in PS…especially since I dont do renders in other apps (just ZB and PS). Would you mind sharing a bit of your workflow? Did you do paintovers in PS?
Wow! Excellent composition!
Good work - keep it up
can you capture your photoshop layer and explain a litlte bit why and how you order them? How much render of zbrush you did?
A well-deserved top-row - Congratulations!
Thanks for all the comments folks. (Cheers leemale. )
As for PhotoShop passes. I’ll post a few more. I guess the trick is to get your model, either polypainted (I didn’t uses textures or Uvs etc.) or UVmapped, as close to what you want as possible within ZBrush. This is easier if you are working from a rough sketch with rough colours schemes/ lighting plan in it or from the background you want the model to appear against.
Either match your scene models to the background or match the background to your scene models. I find a bit of planning in relation to lighting beforehand helps backgrounds and models (rendered seperately) sit together better. I used 2 or 3 saved out lighting ‘rigs’ for his piece. Once you have your base render you can overlay shadow, gloss and lighting/highlight maps. I have no concrete method for this. I just returned to the saved document in ZBrush and tweaked the lights and rendered more passes as needed. Again, whatever makes it fit better with the background.
I also render out a flat render with each different object as one flat colour so I have a layer for making selections.
A few different renders of cavity maps overlaid can help add grit and detail.
I experiment a lot with layers and how they’re ordered in Photoshop. There’s no real right or wrong in terms of order I guess?!?! It’s good to group things as gloss, lighten, shadow, cavity etc. I’m hope this is a help in some way? 
Beautiful, so beautiful!
This is just amazing work man. 5 stars!!
Can u just walk us through on how u rendered all the passes in zbrush.
I would realy help!
Thanks.
You’ve got the deserved toprow
Well… I rendered a base image from ZBrush models polypainted and posed with no shadows. The lighting was centered to get a fairly flat result.
Next I rendered out the shadow and light layers. I adjust the lights according to the scene lighting and usually try to have short shadows (and as close to a ray traced result as possible). I rendered out many lighting and shadow layers and tweaked the lights direction and values etc. Whatever makes the model sit in the scene properly.
The cavity render was a no shadows render again just black and white. I also do gloss, metal renders etc. I use various materials throughout this process including a few matcaps for experimentation. The base turtle and tower are rendered in a human skin matcap. Kind of strange but it wworked okay for my purposes. I usually try to light the matcaps in line with the overall scene light aswell if possible?
Then I brought the lot into Photoshop and used ‘overlay’ and ‘darken’ with cavity maps. ‘Lighten’ and ‘darken’ and ‘screen’ with shadow and light(and highlight) layers. I also used a fog render for a hazey effect. I did a lot of masking out what I didn’t need by hand and then touched up and added small details to the final image where needed. I did the same with the landscape but used some ZBRush fur to give the impression of grass here and there. The landscape was rendered in bits and blended together is Photoshop.
Hope that’s helpful?
Yes that was really helpful. thanks for your time. good luck!!
Really nice work!!! well deserved top row