Akko bending forward holding her ankle (like reference image, but looking backward so we can see her face and butt at the same time) skirt flip and her butt is red from spanking and she is making annoyed face expression
Diana standing behind her, armed crossed, holding her Magic Wand in right hand, making expression as reference.
a flaying wooden hair brush, it's surrounded in greenish magical aura, flaying in the air behind akko butt as it spank her repeatedly .