Initially I was thinking ape-like creatures for the demons. I think chimpanzees are generally horrifying and that it's weird that people sometimes think they look cute or friendly. After the first batch of concepts I'm starting to have doubts. I think my creatures need to look more unearthly/demonic.
I think I understand the centurian armour well enough now to draw it. I want to make it look more appealing though. I've been drawing it as individual bits so far and it looks a bit funky.
I'm liking the look of the sculpted bust at the bottom. That's something I'm aiming for with the overall look.
Planet of the Apes
Roman armour and weaponry