She's a Naga that can transform into a venomous snake.
I just finished playing Muramasa few days ago and have been listening to the soundtrack since then. It's such uplifting and inspiring music!
And I absolutely love the art of Vanillaware's games, I know this is nothing like it in style of painting, but I did take inspiration for usage of color from their art...

Started with briiiight pink background-color, first time I've ever used such bold color, but it was fun!
Line-art is by *
meisan, colors by me (photoshop)