>>39816329The thing about these illustrations is that Sugimori did the mugshots, though I have no idea if he did the 90s gradient coloring. I'd love to think that for at least Gen I and II, every Trainer possessed a quick sketch by Sugimori as the reference material for the sprite artists. There were definitely multiple sprite artists in Gen I, but in Gen II, all of the sprites seem to have a unified style. Compare the Spaceworld demo Houndoom to the final result and it's like comparing RG Charizard to GS Charizard. But imagine a Stadium remake with higher resolution character portraits using Sugimori's art as the direct reference.
I bet a good amount of those are lost to time though.