I never pictured him in full plate myself? I guess I was thinking some lighter variant, like chain, scale or leather? But being giant size, that would be pretty thick leather, and huge thick ringlets of iron

Oh and the ballista im talking about is form Lintkings suggestion, Ballista bolts. I just would like the shield to be a big Hoplon type, like this :-

hoplon.jpg although maybe if its not too overpowered it could be magical, not sure in what way though.