It has a happy ending, she died again and restarted to the point before she died the first time and killed that Shen Wei'an chick and got together with Fu Bainian. (The real) Chen Mei Mei is still alive as well.
OK, you're gonna think the ML is a rapist, and for the majority of the novel, he is pitched that way BUT 1) he is able to see the MC's thoughts and knows the MC actually wants it even though he says and acts like he doesn't (because if MC says and acts the way he wants, that world will collapse and his mission will fail) and 2) as I mentioned, the MC really, really, really wants it
The ML has been following the MC through all the worlds but for the first half of the novel, he only has memory of the first world he followed MC to (that we don't get to see) because he inadvertently caused the MC to collapse the world, so as punishment, he has no memories of any of the worlds he follows MC to except the first, which is why he acts sad and lonely, not knowing when he'll see MC again. He doesn't know if he has joined him for two worlds or two hundred, he only has memory of the first. LATER, after there is a bug in the systems (correct, there are SYSTEMS), he regains memories. He still has to act out his roles and live to the end of that character's timeline though.
The dragon form smut scene made me uncomfortable but that was due to.... the vivid imagery of pain. >_<
The ML, I mean really, he is so~~~ PURE (of heart and mind, though they do papapa, he's just the purest cinnamon roll everrrrr). The ML's eccentric master has a lot to do with how pure and GOOD he is. The MC is just so bada$$ and it's hilarious how the ML thinks he's weak and helpless in the beginning. From the time ML finds out MC is his fiance, he treats him and treasures him as a wife, right from the start, no questions asked. AH! He's so precious! Can you tell I just wanna put ML in my pocket?