spoilers( maybe,i think not sure though)my opinion only
on this current chapters sol was literally being suspicion of her instead of getting to know her better and about yomi...well
no, because if you've read the current chapters in the raws you'll see that yomi really loved lana even if she isn't a villainess,the only reason that yomi thinks that she's being brainwashed is because that wasn't how she was before and lana was indifferent of others.When they were young yomi was the only one who was there for her despite being pushed away. On the recent chapters he literally even cried because lana almost got in danger and wad even ready to sacrifice himself for her.
He really did liked her even when she was bad or not and he was literally happy when he saw lana smiled unlike the current lana who used to have a gloomy look.Yomi was always waiting to see her smile and besides he was only worried that they did something to her while he was because lana used to get treated indifferent unlike her sister and yomi wad the only one who new that, lana didn't have anything except for yomi despite him being pushed away by her. He may look like a masochist but he's only like that for lana,he's really caring for her even then and now......
bruh ..........if you were in yomi's position wouldn't it be weird for you to find out that the person you used to know changed so mush like a different person, he did that because he thought they did something to her for her to act that way because above them all yomi was the only one who knew lana's childhood ... besides......uhmm...... sol he's reaction is not that good for me..he may be confused on his feelings for her nor he like the elder sis for saving him and tried to understand his suspicion
sol was literally treating her half hearteddly because he still like the older sister one... it's like whenever he's saving someone lana was always second and her elder sis is always the first priority unlike yomi who would do anything for her sake but if you prefer him he may have a chance because on the recent chapters sol will somewhat understood his feeling for her(not sure though, didn't understand much because it doesn't have original translation)
and for the hero(forgot the name) don't like him that much since he's like developing feelings for lana (not sure if he only wants to see's her as a sibling or not)even though he already have her elder sis with him
yomi may be possessive but he truly is caring for her and lana was his best priority unlike the others so yomi was literally the best in all of them
I know a lot of people are rooting for Yomi, but he only loves the “villainess” Iana! Wouldn’t Sol, who wants to know what she is truly like, be a better option?