(I was able to read this up through the end of the third arc at the time of writing this comment)
tl;dr summary: su luxia is a player of a transmigration system where can transport herself across different worlds/stories into the body of the second female lead to exact revenge on the main male and female leads with dimension-bending, overpowered tools and gimmicks.
it sounds so damn ludicrous, so wild and wacky. and that is EXACTLY why you should read it.
aside from being a very satisfying revenge story taken up to 11, it serves as a fun and sometimes scathing satire of the stories su luxia infiltrates. nearly all of them are isekai stories themselves (or involve transmigration in some form) and all involve romance to some degree. su luxia and her helper's comments are lightning-quick at pointing out the many flaws, bends of logic, or otherwise warped sense of thinking exhibited by the male and female leads of the story they're in. like, really, how can the female lead of a vampire fantasy romance be on board with potentially ending the entire human race for her vampire boyfriend? who was already engaged to someone (su luxia's character)? who treats this fiancee as if she owes him her life and should always listen to him? don't worry, these crazy b-word and asshole guys will get their dues. cheating bastards, really, must die and su luxia does her audience the great pleasure of making sure the revenge she exacts is as gruesome, thorough, cold, and satisfying as we readers could ever want. she's incredibly calculating and cruel, and we the readers can do no less than root for the lead couple's comeuppance.
(if you're wondering about the gimmicks su luxia uses, she has to redeem points to gain items from the transmigration system she's in. she uses these super items to help her revenge plans)
read it if you like a cynical and satirical take on the isekai genre, particularly isekai romance. su luxia's unrelenting sadism against cheating bastards is a joy to read, especially when she finally gets to put her intricate revenge plans into motion.