Perhaps it implies that the author plans to conclude the part of the novel dealing with an engagement in a rather abrupt or unforeseen manner. For example, if there are a lot of twists and turns in the relationship leading to the engagement in the story, now the author is signaling that this phase is about to come to a halt in an unexpected way.
A jilted lover who was supposed to be engaged but was betrayed. This character would be full of anger and resentment and would say 'ill end this engagement novel' as a way of vowing revenge or simply to show that they will put an end to the whole engagement - related story, whether it's by ruining the other person's reputation or by some other means.
Here are some recommended completed ancient romance novels that involve marriage contracts:
1. "Out of Favor, White Moonlight Strikes" by Dong Jianing
2. The Precious Concubine by Shengshi Qingge
3. Yu's Spring and Autumn Annals by Lin Jiacheng
4. "The Cinnabar Mole in the Heart of a Powerful Official" by the Sleeve
5. "Getting Red" by Say to the Moon
6. "After being, I became everyone's white moonlight" by Crisp Peach Card
7. [Jiao Shu] by Xumi Pupu
8. "Forgive Your Majesty" by Cheng Shiqi
9. "Spring is just right" by Shen Chou
10. "Dimou" by North Face and South Face
11. Mirror Flowers by Twenty
Please note that these recommendations are based on the provided search results and may not represent an exhaustive list of all completed ancient romance novels involving marriage contracts.