I finished the HG Barbatos Lupus Rex in a black iron style.

I've also created models using gold, silver, and copper as themes. Please check out my gallery if you're interested.

*I used the Iron Blood Coating version as the base kit.
Basic modifications included making the movable parts non-movable by gluing them together and sharpening the tips as shown in the diagram below.

For the painting process, I applied a black base coat, then painted the black iron color over it. I expected the black iron color to have high opacity, but it seemed to be surprisingly affected by the base coat.

Iron | のり's Gunpla works