To answer your question, madimb, I used watercolour paints on canvas for the background to give it a soft, slightly inconspicuous aesthetic compared to the fighters. I used acrylic paints to have the Owain, Severa and Anna the Merchant stand out from the background and draw the audience's attention. Owain is dual-guarding against Anna's spear attack with his Brave Sword while Severa prepares to cast Nosferatu.
I'm glad that you noticed Anna's confidence based on her facial expression - I spent hours trying to get that face right!