The first world really seemed like a "snu snu can fix everything" type of story and the romance at the start seemed shallow, because most of what they did was snu snu and the side characters just seemed to be problematic for the sake of being problematic with all sorts of unnecessary drama, even ending with a bad ending (personally, I have no issue with the ML doing the do as a snake but that is another thing that might put off people).

The characters are clearly not OP, the amount of times the MC got hurt or almost died fighting (especially in the fifth world) really made me anxious that the story will end that way and the worst thing is, is that sometimes it did. I am so grateful for the relaxing primitive world that came after all those heavy hitters from worlds 3-5 because if you're reading the story, you'll need a break from all the doom and gloom. I consider the endings of each world to be a good ending if they end with the ML's evil value dropping to 0 because that is the ultimate goal of course, even if the MC and ML are not able to live out their lives happily together, so be prepared for tissues.

Some info on the fifth world. The MC turned into a guy and has to befriend the ML in prison to be a spy for the police (she never intended to follow that through though and just wanted to move to a different to escape the horrible fate of the original body). They become tight "brothers" but never crossed the line (so no snu snu) because a side character who was an undercover police (hate that dude, you do so many despicable things but still manage to get away scot free) was also tasked with sending info to the cops and as the MC usually has bad luck, the blame and suspicion fell onto her after the police almost captured them. So of course, she ends up dying in the hands of the gang the ML leads (although the ML tried to keep her hidden). In the end, the ML only found out she "loved" him at the funeral. Tbh, I decided to share this info because I thought this world was treated really unfairly, in all the other worlds, the MC and ML were able to "love" each other but in this world it's always kept a secret and given that it was kind of a BL storyline, it just left me feeling iffy.

but she's already realized that every person is the same and is even looking for a mole behind the ears of the target, because that's how she knows that it is the ML, if I recall correctly i think I've read too much quick transmigration stories and might have mixed it up And also after she found out, that's where she really began to be interested in these worlds and learned how to truly love the target in every world. Unlike in the first world, where it seems like she's only there for the sake of it and doesn't really care about what's going on around her. Which I think is really a great development

Not every arc has a happy ending which brings much needed angst to the plot. In one arc she transmigrates as a male prisoner. The ML is a leader of an underground criminal organization. She dies in this one before the ML has a chance to express his love to her.

The FL realizes pretty quickly that it's the same ML world-hopping with her. She recognizes some subtle tells (ML's mole behind his ear, aversion to carrots) but puts on a dumb front to fool Xiao Nan.

Example: in a chapter where they introduce the child of fate, knowing the development between the child of fate and the villain... it seems intuitive to suspect that your ML is supernatural.