What he said about Yihwa surpassing Ran is not very important actually, he immediately said after that he himself doesn't know what will happen to Ran in the future. I personally don't think she will surpass him, but we will see.
Androssi has gotten plenty of development, a good chunk of S1 was about her development. With the story of her adoption and how she managed to survive, she became unable to trust anyone. It's because Baam's affected her that she began to trust people and open her heart with others, who became her trusted companions. To the point she is now traveling with Anak, without all of this Anak would be dead. The reason you might think her character didn't develop at all is probably because she is too daring, sometimes arrogant even, it is her fatal flaw. But that's a side of her that I personally like. She can be a bit too capricious at times as well, it annoys me a little sometimes but I don't really dislike that either. Not sure if I can explain it properly. Her flaws make me like her even more I guess? I am not sure how SIU does it, she is cute, she has depth even though her hot blooded attitude might make people forget it, she does her best to protect the ones she loves even though the way she operates is not always the best. I really, really, like Androssi

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She is by far my favorite female character, and I find her character traits go well with Baam, their interactions can bring the worst or the best of her(more often the latter) Baam is a patient guy and she affected him. Her talk with Baam about his goals and his relationship with Rachel was great, her reactions during their date were great, she was great when she complained to him when he was troubled after the "death of Rak and Yihwa. Androssi is great

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I like Yeon a lot. Before she was incredibly incompetent, naive and prideful, now she is much more competent, knows everything is not as simple as she thought and reliable. I like this, but her flaws have been toned down too much IMO.