SOTERION: Castle Lurin

I have been asked to create a modular castle for an upcoming game 'Soterion'. The castle will be modeled after the Castel Sant Angelo:

So as of now, I have created the wall pieces, the guard towers, and the castle base. I just recently began the top portion of the castle:

The modular pieces of Castle Lurin...

An pre-visualization of how the modular wall pieces snap together...

The top of Castle Lurin in progress...