
I'm waiting for Sohwa's reaction ...

I don’t think so. He does care (many places of the manhwa supports he does) and he would beat the soul out of Geum and maybe Chungha.
Even Rihan knows Sohwa is in love with Miha. Sohwa has been raised to see Miha as a piece of trash and is constantly conflicted. When his memories return that is why he gets all cocky, he probably had the best two weeks with Miha and knows Miha does love him. If without the drama from Chungha and Geum.
Maybe Sohwa and Miha would probably return to how it was and will get angry it was not like the two weeks and probably have to reflect on things. We will never know how Sohwa would had acted but now Miha is in danger.
Even if he was not in love with him, his half brother.
To “Something” that he claims that is his and he does not like Geum.
So, he is going to be explosive.

I can understand what you are trying to say but right now let's say sohwa don't love miha, insted miha is like sohwa's most favourite toy...
You know, it's relatable that sohwa grew up in such environment that made him like this, but more than that it was miha's unconditional love that made him like that....
miha never abandoned him and loved him regardless what ever he did and however he treat miha....sohwa doesn't know miha's value bcoz miha never left him and he has never been felt alone....

I agree with most of what you said besides the first paragraph and something else.
When Rihan goes to Sohwa to help, Sohwa said a few nasty things to which Rihan read in between the lines. He didn’t take it at face value because he knew Sohwa was airing and hiding his feelings. If you take that Sohwa is in love with him and he is conflicted between that and how he was raise, Lots of his actions makes sense. Some of his actions does not make sense if he only thinks Miha is a toy.
Sohwa does not like it when Miha is trembling. Though he picks the wrong things to do like when Miha is trembling he does something to make Miha tremble more (choking him) and be scared of him more , smart Sohwa.
I don’t think Sohwa knows Miha is in love with him, loves him yes. I don’t think it is Miha‘s unconditional love that help this but Miha’s being scared and obedient over what he has been through over the years. it is how he coped over the years. Also, I don’t know if Sohwa actually knows he is in love with Miha. But the manhwa does seem to heavy indicate he is.
Miha just left him and he is alone at the moment, while it has been a day. He is nervous because he is smoking a lot.
The points in this story are Ryousuke is a spoiled brat and cute at the same time. Can relate why they are falling love with him.