>>22944761If you're familiar with Sugimori's style you can tell pretty easily by just looking at it. Compare it to Mega Rayquaza's Sugimori art, for example. The palette is different, for starters, but that's a minor difference. The only thing truly different there is that the artist filled in the dark areas (like around the eye and the dividing lines) with pure black, whereas Sugimori tends to use dark grays.
The main giveaways are the outline, the way it's shaded, and those solid white highlights/streaks on the pink parts of the art.