>>1457257Did some research on the changelogs + the game's github page and the exact timestamp for the first upload of the character art was:
Feb 18, 2017, 7:10 PM GMT
Thank you once again for the help!
Now, on sadder news. After sorting by oldest and going from the date said of repost (2021) and backwards on buhitter until the very first post of the tag, I was unable to spot the artwork again, meaning the original artist either: a. asked for removal, b. deleted their post/the account, or c. the art was not originally, or alternatively, posted on twitter at all.
I even made sure to pay very close attention not to miss anything, and expanded the search on artists that had similar artstyles, but to no avail. Of course, there's room for error there, but even then, I am not very hopeful on that end...
Even though I already scoured boorus and archives before, I might try doing that again. Hopefully a light will come out soon.