It looks more like Wart than Bowser Jr...
Try thinking of what he'd look like from a different point of veiw.
It looks like Bowser Jr. in his teens.
That's because this one has scales.
What's Roy doing with his wand?
Well, in PM2, the magikoopas had an attack that look like multi-colored triangles, squares, and circles. That looks very similar to what Roy is doing.