Zuriyel

I agree. I still need something like a scene, where we see her learn about the hard life that WR lived, which is what the maternal grandmother did.
Despite their reunification, she still seems rather oblivious to it.

I didn't say "the main antagonist", but "one of the main antagonists" and "a main antagonist", which implies that there is more than one.
"The main antagonist" would mean that there's only one big bad villain.
And I don't mean in this in a derogatory way, bcos that could be misread as such when you're just typing instead of talking to someone verbally.

I agree.
They could easily have elevated his character, if he had gone to Rao's residence, telling her that even though he announced that he's there to court her, it was actually bcos he knew that Lu Zhao was being a dunderhead and making him jealous would be the best way for Lu Zhao to realize his feelings for her.

While I do agree with you on this current arc not being up to par with the first 16 eps, the synopsis here on MDL clearly describes a different show than what you were expecting.

In regards to the villain, Han Liao, I do think it's an issue of how they're turning him into comedic relief while also having set him up in the first arc and now in the latest episode to be one of the main antagonists.
You can't have a main antagonist that gets undermined constantly in a comedic way. That's just not interesting.
Kylo Ren in Star Wars lost steam as an antagonist bcos he was portrayed as a skilled warrior, who in the end was defeated by someone with no training.
What they did with Han Liao was even worse, bcos they also turned him into a joke.

I don't want to agree, but I do. Aside from what you mentioned, we also have Han Liao, who in the previous arc was a complete snake, who killed his wife like she was nothing, just to buy himself more time.
Now, he is comedic relief and presented as a potential love interest who's trying to thirst-trap.

Yeah, I think it's more that she changed her tune after experiencing how terrible palace life was.

I think it's also that their relationship started on a lie.
Now it can start all over again with sincerity.

Same. I need something like the confrontation between Lex Luthor and his dad in Smallville.

Lionel Luthor: I'm sorry... if... if I had known... things would be so different between us... son.
Lex Luthor: Yes, dad. You might actually have loved me.
Lionel then tries to hug Lex, but Lex shrugs him off and walks out of the room.

Lu Zhou's like: "She's not a demon! I didn't marry a demon! The heavens have eyes!
Grandma! Sorry for what I said! You were right! She IS a lucky charm!"