i corrected the lighting and composite of Demon.
thanks for many advice.
i finished this work about in 6 days,
and today i will show you the process;)
i tried to create basemesh with Dynamesh.
then subdivided and sculpted detail on about 5 million faces.
After that, I brought this model to maya after decimate in zbrush
and I checked if displacement map is all right
this is raw image after i did lighting and shading with SSS and Mentalray.