Her one-sided feelings towards raelle are creepy. She keeps on forcing her feelings onto Yunifer to the point that she's trying to sacrifice herself for her, not realising this would lead to bad consequences for Yunifer. She did the same thing in the academy, Raelle pestered yunifer and Yunifer got misunderstood and seen as the bad guy. Ishid saw all this so its natural he doesn't like her.
Please read this on the webtoon app. It's called UNHOLY BLOOD. It has the same number of chapters and you'll be supporting the author.
And it's FREE!