AH :
Good with LGBTQ romance. Even censored romance works as long as the romance is still a central part of the story and not just a subplot. Like The Untamed.
Okay, im just gonna rapid fire some out and then give a brief explanation of why they fall into the category(Some will have romance but its more one sided)
1. Word of honor: I dont know if you've seen this one but ima assume you have but person in power wkx loses his power and gets overthrown all that good stuff and romance is part of the plot not as much for him since it is censored but for Gu Xiang and Wei Ning there is alot of good and cute romance.
2. Golden blood is like war between gangs or crime families and theres alot of exchange of the upper hand between the gangs and there is romance in it. There's a couple times where one gang will lose power and its like a good drama if your interested in gang rivalry.
3. Kinnporsche: Kinnporsche is another gang or mafia related one and in it there is again rivalry but what differentiates the two is there are many times where the main powerful lead is alone or stranded and has to be saved or times where his empire falls or where hes vulnerable. Even from the first episode he is put in situations where he has to get help and romance is super big in kinnporsche.
4. Bad and crazy: Bad and Crazy is iffy for me but basically this guy has a split personality disorder and sometimes he cant fight and hes bad at his job and then the other half is a powerful strong person who can do anything and hes exactly like who he wants to be. There is romance. I wouldnt know if i would classify this as a powerful person losing power but i would say its a person who is sometimes a powerful person and sometimes weak.
5. Kei x Yaku: In this one guy is in the yakuza and the other is a police officer and throughout the show they fight together to take down a guy in power and throughout the show you can see gim slowly getting weaker and Kei and Yaku slowly winning. It is a censored adaption of a romance but there still is chemistry and they live together.
6. HIStory 3: Trapped: Another one where the powerful guy is put in positions where he has no power and in the end he gives it all up for his romantic partner. You should watch it if you like seeing y'know emotion and sacrifice for the sake of the romantic interest.
7. Weak Hero Class 1: This one is almost reverse. It's a weak character becoming powerful only to have it ripped away and the restored throughout the series. This is a very emotional and also gritty show its like watching high schoolers beat the ever loving shit out of eachother. He does lose his power multiple times and he is bested in fights many times but he bounces back.
I know some of these are not gonna suit your taste but i added them just because they were really all i could think of. But if you end up watching any of these tell me if you liked them.