beta
https://tvtropes.org/pmwiki/pmwiki.php/Literature/VillainsAreDestinedToDie#:~:text=Callisto%20ends%20up%20being%20Penelope's,always%20wanted%20with%20her%20life.
This has every single spoiler for the entirety of the plot, as well as naming interesting literary troupes present (it’s so interesting, I ended up spoiling everything instead of reading the novel ver. like I planned, and there’s like a whole ass 4-page list of every troupe fathomable)
If not, and you intend to pick up where the manhwa currently left off, if I’m not mistaken it should be around chapter 156 and you can look up any aggregator novel site and read it off of there (albeit, depending on the site and when/where the chapters were taken from, the translation quality can vary)
Here’s a link for that as well (this one has decent translation!):
https://www.lightnovelworld.co/novel/death-is-the-only-ending-for-the-villain-518/chapter-156
Also, since this isn’t too much a spoiler, the story IS a happy ending!