another spoiler, lol.
i thought she was the fallen sister of god, the mother of demons? that's why she can't be the "sun" but only a "star," and that's why all of the demons subconciously listen to her and why holy water doesn't work on her, but works on her "children." wasn't it something like god's jealously about how much people loves his sister that he created holy water and accused them of being evil to purge them and stuff?
i found the novel on https://nyxscans.com/series/my-possession-became-a-ghost-story-novel and https://anubisscans.com/novel/i-possessed-someone-and-turned-into-an-urban-legend/. nyx scans has better quality of translations (free up to chapter 45), but anubis scans has free chapters up to chapter 108. there's also the original korean novel on https://ridibooks.com/books/4956000066?_rdt_sid=category_books&_rdt_idx=3 too.
Not be sound religious or anything. I grew up in a Christian household. A lot of the Bible depicts God or angels as ‘scary’. If you ever seen online those photos of “real angels” or “biblically accurate angels”, those are depictions of what the Bible says SOME (very important, not all angels are like that) angels look like. I’m pretty sure their depiction of Evangeline is supposed to immulate that. These angels that seem scary to humans but are the most holy. I honestly love this depiction of holiness. Humans are beings that cannot reache true holiness because of sin. It makes sense that good or holy would seem so scary when you can never be truly sinless.

GIRL LITERALLY, WHAT ARE YOU???? A DEMON? A GOD? AN ANGEL?
Every time someone tries describing her, is so fucking metal. Not only are the people confused as fuck but the readers are trying to figure it out too! There’s just so many possibilities