For the first picture, I would prefer cropping the upper dark part away to make it look more dramatic. I would also shift the camera a bit to the left so the whole shadow of the boy gets in to the frame.
For the 2nd picture, I really like the natural light that comes from behind the subject. It makes the wing and the halo ring glow. I only wish the person behind the girl in the center were a little bit taller so his/her lower part of the face didn't get into the picture.