Since this is unpopular opinions:
I kinda liked The Great Seducer for what it was worth. I judge dramas based off of overall enjoyment. Many disliked this drama because of how "toxic" the characters and the relationships were. Most don't understand that's exactly what the writers were going for and had planned for since the beginning. It's based off the original French novel titled "Les Liaisons dangereuses" by Pierre Choderlos de Laclos. It deals with lots of heavy topics and brings attention to the dark elements of human nature.
Yes, the relationships were toxic because they were supposed to be portrayed that way.
I prefer analyzing and appreciating how the cast has captured the dynamics of such an unhealthy relationship rather than continuing to watch the same boring beautiful faces with little to no plot but the love between two characters. It's cheesy and hard to swallow over and over.
Furthermore, it dealt with mental illness. Soo Ji was on psychiatric meds which she stumbled upon from her own mothers collection. This she mixed with alcohol and would frequently have maniac episodes. She took it for anxiety and depression. Anxiety medication is highly dangerous and yet it is one of the most overlooked. As they say, take a benzo and you might become relaxed but take it with alcohol and you might become so relaxed you stop breathing. I feel like this show gave attention to that. I mean, let's remember the ending, how Soo Ji ended up in the hospital. It's no surprise that she woke up in that white room hooked up to machines due to her attempt at suicide with the anti-anxiety drugs downed with painkillers.
Self-harm is another topic this show discussed.
This is becoming a trash rant so I'd rather save it for a blog.