Smth with similar… dark.. vibes to this (rape, torture, abuse etc- a strong uke who is physically and mentally broken down) is “I became a slave to the man I abandoned.”
More lighthearted (no SA/abuse but some angst) is Office Hero. Similar to that is “I think my friend is going to become the demon king” but it’s less serious I’d say.
Then there’s the old classic Kingsmaker, and recently Regas, though the ukes themselves aren’t the knights (the tops are… well, tbh they’re technically kings). Both deal with pretty dark themes happening around the couple, not between the couple themselves though (and have extensive plots).
Aaaaand, if you’re after a real gloomy, mentally unstable uke in a medieval setting, there’s Antidote (tho, imo, the bottom is pretty insufferable- the dainty, delicate flower type)
Winterfield has a cool knight bottom but it’s a wholesome, slow burn romance.

does anyone have any other recs with knight ukes, especially gloomy ones, this genre is so peak but so hard to find #-.-)