Examples please, I’m curious.
Take Baams conversation with his former self and Dowons conversation to Cha about Baam. Dowon believes that Baam will just change as he gets more power while Baam reinforces it to himself about not being greedy as he continues to move forwards. So, both Dowon and Baam have the same concerns about him, Dowon believes he will just become another monster like Zahard while Baam is telling himself not to become greedy and hope that the ones he wants to protect stay by his side.
You also have the fact that Dowon was sealed away by force by using her kingdom as a hostage against her will, so she had to seal herself away and looking at how she felt she explained how it clearly hurt her. Baam is the same, his friends were used as hostages and forced to join FUG and become a monster and be hated by people in the tower.
You also look at how they behave as well and their morals. Baam is a kind person and the thought of killing people hurts him; even using souls to save the people he cares about hurts him. So while he won the first fight on the first wall he was still sad that he had to use those souls. Baam has compassion for people the same way Dowon does. The things that Dowon is afraid of about tons of people dying is also something Baam is bothered by as well. Baam is in a situation where there are no right choices, saving his master is not the right choice, but neither is letting him suffer like that a right choice. Baam is making wrong choices but is justified to do so. The same way Dowon is making wrong choices to fight alongside Zahards army but is justified to try and save the people she cares about i.e. her friends.
Dowon and Baam are two sides of the same coin, they have different ways of going about doing things, but their goals are similar as well as their beliefs. It is not sufficient to say that the way Khane described her sister as kind, but cruel is something that we can also describe Baam as being a kind, but cruel person.
Dowon wants to save people, while Baam wants to save the people he cares about. I think that the reason why they are so similar is because of their self-sacrificing ways. Both Dowon and Baam are willing to sacrifice themselves at any given point if the situation calls for it. They love the people they care about enough to put themselves through pain and suffering so those people can continue living.
What has changed is that at one point Dowon was fine with being unsealed as soon as Baam showed up in the tower, but because she learned about what Baam will bring to the tower “Chaos and war” she’s clearly conflicted. She fought Zahard for revenge and to bring people peace and not be oppressed by Zahard. Baam is fighting Zahard as well but not for revenge or even to bring peace but because Zahard is oppressing people and making things miserable. He tells Rachel that he is going to unlock the door and make people happier. Of course, I don’t personally believe that Baam will be the true king of the tower but I do think his goal about stopping Zahard and making people happier will align with the next king of the tower though.
I fuc...ing forgot. Cha and Dowon are in love! So to make Dowon Baams “heroine” you must kill oh Cha and then somehow mombojombo out of ass the relationships between Baam and Dowon. Damn, because of immense useless info that Siu gave us, I weren’t able to remeber that little episode! If you do not believe re read 3-40 chapter.
Dowon: I knew it all along! Too bad! I was thinking if I should say yes when you confessed, but I guess that's not happening anymore, is it? I guess more so than me will be you guys missing me, right?
Cha: Don't talk like you're going to die. You're being sealed. We'll meet one day. It may be a while, but we will meet again, so please let me confess to you like a true man when that time comes.
Dowon: Should I? I'll let you know how I feel when you do.
Cha: What? It's not a yes?
Dowon: Now's now, and then's then!
Cha and Dowon aren’t “in love” their relationship doesn’t seem that deep and reading what she tells Cha doesn't really tell me she's in love with him she was just considering him. But I do believe that Cha will die in this arc, since the 8th son's Anima is at the Nest I assume he's nearby waiting to see what happens and if he needs to show up he can just appear.
On a side note I don’t get why people ship Baam with anyone who doesn’t share his common belief. Enne, Adori, and Androssi aren’t people that would work well with Baam because of who he is as a person. Androssi is one thing but Enne and Adori seem extremely farfetched. I know there are people who don't like Dowon due to how she is currently, but if she is the main heroine then I think Siu will be able to write it in a way that people will actually grow to like her.