You will need to install a user script manager extension to install this script.
This very short script will loop through all possible elements and detect the sankaku anti-adblocker popup by finding unusually long ID names, those are the randomly generated IDs.
The admin of sankaku has implemented some of the scummiest anti-adblock and vehemently defended it in the forums, and locked/deleted anyone speaking out or advising how to get around it. He realized it was blocked easily by ublock, so he implemented randomly generated strings, which ublock isn't smart enough to detect. As of the time of writing, Sept 21, 2023, this is working. I imagine once he knows of this tactic to bypass he will change his implementation to shorter strings and whatnot.
If/when that happens this can be refined to look for whatever new pattern that's come up with. At the very least, delete all div elements that don't match certain named ones that the website requires. I can't imagine he would implement randomly generated IDs for core-functionality of the site, as that would be a bigger headache for him than the users.
There is a brief moment where you will see the anti-adblock, but it will be deleted. I'm unfamiliar with tampermonkey so perhaps it can be made to run sooner to delete the necessary element faster.
Edit #1 Sept 22, 2023 - The site admin has seemingly removed the anti-adblock popup this script was made to stop and added the randomly generated ID to the main div body that holds all the content that this script now removes, breaking the website with this script. I imagine this is a step in integrating the anti-adblock deeper into the website because the main content body did NOT have this long random string as an ID beforehand.
Edit #2 Sept 22, 2023 - Works again, see changelog.
Edit #3 Sept 23, 2023 - The admin is really trying to stop these scripts I hope this is ruining his day.
Edit #4 Sept 23, 2023 - The website was update again, breaking this script by redirecting to a 404 page. But with the script off I'm no longer getting the anti-adblock message, ublock is catching it I think, for now.