The Iron Baroness by Titanilla Pizvor (Twitter, YouTube) is featured in Soul Arts on page 166.
One armor detail of The Iron Baroness is referenced by a symbol in the Demon’s Souls pattern on the endpapers. The number of points on the star could have been reduced from 8 to 6 to match the hexagonal pattern used throughout the endpaper.
According to art director Andrew P Hind (Instagram) he decided to use a hexagon approach for the Soul Arts pattern because of the 6 archstones of Demon’s Souls (source).