>>47940298So first I'm taking them from here:
https://pokemonsettei.tumblr.com/post/644463831370842112/update-more-settei-sheets-found-just-in-time-forIf you open the image in a new tab, there's a part of the URL that says "s1280x1920" - change that to something ridiculous like "s4000x4000" and it'll get send you to another tumblr link, to which you open that image in a new tab and it's the full size image; This is probably something that's only available to newer images on tumblr