This is an IB brought to you by a weight loss story in a rather low quality isekai manga. The change happens in Chapter 13.
There is no English translation as far as I'm aware.
https://kissaway.net/read-ellie-gold...hapter-13.html
EDIT: I should've mentioned this in case the link gets broken, the title is: ellie golden to itazurana tenkan busu de debu demo ikemen elite
Meanwhile, I've found another worthwhile TF in the webtoon White Blood in Chapter 13 where a guy gets IB'd after turning into a vampire.
https://shieldmanga.club/read/manga/...to/chapter-13/