I found these rough in the link below: https://ishanator2001.tumblr.com/post/178671965347/ahri-short-rough-w-patreon-twitter And the images of the original resolution could be obtained from Metal Owl's discode server. So, the works is confirmed to have been released exactly on October 3, 2018. (in KST, UTC+09:00)
It was very lucky. Unfortunately, Patreon, where he first posted them, disappeared. Also, his collection of past works before 2019 posted on pixiv FANBOX includes "only completed works." Besides, he lost all of his artwork's raw file from 2011 to 2018 due to damage to his USB flash drive in May 2021.