Not manhwa (bc honestly I have yet to find a good manhwa as good as ennead when it comes to the writing) but try danmei (Chinese bl novels)or baihe (Chinese gl novels) I feel like they are just as good. while they mostly have good romance stories they also have a very well written and complex political setting that doesn't take the spotlight from the couple but also make the story more interesting.
There are alot of novels to read the most popular are tgcf or mdzs or even svsss (all by the same author, they are fun and easy to read. A good option if you want to start reading danmei) there also QJJ an enemies to lovers (my favorite) also 2ha for more unhealthy relationships if you prefer that . For baihe you can start with JWQS (the political plot is heavy so you gotta be focus)
And ofc there are alots with either historical or modern setting just try to search for one that suits your taste.
omg thank youuuu i think this what i needed!!
ur gonna love antidote (harusari)
i just finished Ennead and i need something to give me that same feeling. a story with political intrigue and interesting characters