Now that is a stank face, and I agree with your TL decision re:names! For a manga set in China, I do think that the romanizations should be more in line with actual pinyin.
It seems like he betrayed her because perhaps he promised and she hoped they could live together happily? And after orchestrating a scene where she would have to take action, he ordered her to kill him, so he "used her until the end"
So this chapter was so confusing that I had to refer to the Spanish version (even though I'm not very good at Spanish) because it was easier to figure out who was talking to whom about what.
For a quick recap for those in similar boats:
flash back— 17 years ago at the imperial palace, the count...