Actually, the composition bothers me and doesn’t really convey that immovable strength. I think that’s because of the way the creature looks like she’s liable to slide off that orb she’s sitting on.
I would make her sitting alert and erect, not leaning to the side - the whole composition’s left-heavy (our left) and makes me uncomfortable and not in a good way.
I agree totally with what people have said about the confrontational gaze - you need the figure looking out, directly at the viewer if you want to indicate confidence and/or menace.
And the wings provide so much opportunity for ornamental beauty - more variegated color could definitely focus attention on the figure, not the background.
Somehow too, the head and wings seem to belong together but the body seems separate - maybe thru a nice transition from neck to chest, color-wise, you could make them look more unified, as if they belong to the same body. As it is, I tend to almost see it as a big bird perched atop a headless humanoid body.
Anyway, lots of good suggestions from the forum - looking forward to seeing your next iteration! 