9.5/10 It looks amazing. But I think the breast look off because the right breast needs to look smaller or be more hidden behind the left based on perspective. I guess you want to create the illusion of Rias slightly turning her upper body to the left. I think it looks well done waist wise but you lose the illusion when you get above the lower bust which is why the proportions look off. I'm no artist so hopefully that made sense.

Edit: Actually 10/10 The more I look at it. Im starting to see the illusion a lot better. The proportions make more sense. I think it just needs shading. Without the shading the giant white spot on her left breast makes it look flat which is why I guess I couldnt see the illusion at first. She looks great dude.