For example, the necromancer Mary is said to grow stronger in the novel, but never performs any feats of strength that would impress upon the reader that she has really grown. This is the same for Ron, Beacrox, Choi Han, Raon Miru, Toonka, Witira, Archie, On, Hong, Hannah, literally everybody besides Rosalyn and Lock. Only those two display growths in strength that don't come from obtaining some new power like Choi Han's inherited black yong or a new ancient power.

The White Star is a creative antagonist. The idea of a man willingly embracing a curse of reincarnation in order to gain power and ascend to godhood is novel. He's also really intimidating in the beginning. TCF does a good job of showing off the power of the White Star the first time he appears. He overpowers everyone including Choi Han and the ancient dragon Eruhaben all at once. However, over time he just becomes way less of a threat since he loses almost every time. It almost seems like he gets weaker, even as he canonically grows stronger. In the end of part 1, as the White Star becomes complete, Cale still 1v1s him and and wins, TWICE. The White Star literally gets nerfed.

All that stuff about hunters and single-lifers could have been left out of the novel entirely. There wasn't really a reason to introduce those new concepts. The story could've been self-contained and ended with the defeat of the White Star. It didn't need to be a story about Gods and Demons.

You cannot say in good faith that Cale Henituse develops as a person. At least, not throughout the story. He behaves exactly the same at chapter 750 as in chapter 150. I know the novel has an entire arc where he goes into an alternate dimension and "overcomes his trauma" and saves all the people that died. But, seriously, ask yourself this: Did any of that even matter? The novel can say Cale overcame his trauma, but what really changed about him? He acts the same, thinks the same... he IS the same. If Cale, for instance, stopped sacrificing himself after resolving his trauma or changed anything about the way he acted, we could say that short term character development happened. A big part of this problem is the way Cale is written. He's too stoic. He's like the epitome of the toxic masculine "men are supposed to show no emotion" notion. There is only one instance in the entire novel when Cale shows any emotion besides anger or annoyance, and that's when he wakes from the God of Death's dream with Lee Soo Hyuk. He cries. I thought that would have been such a good emotional moment, but the novel has to reinforce the fact that Cale is not actually sad, just that he's crying for some reason. Why bother? Why can't Cale be sad? Why can't he cry? In that scene, Rosalyn noted that it would've been normal to see Cale cry out of anger instead of sorrow. Why? Cale is human too, so he should be written like a human. And humans get sad, humans cry. Humans aren't cold, collected robots. This stoicism that Cale is afflicted with rejects any change that comes to him. Perhaps part 2 will open Cale up a little more and allow for some development, but I doubt it.

In addition, the original Cale Henituse (the one that inhabited the body before Kim Rok Soo took over) does indeed change from who he originally was, sure. But that doesn't count. We don't see any of it happen, we just get to see the starting point and the end. Imagine if a character in a novel is shown in the beginning, and then once again in the end and that character has changed a lot by then. We could say that they went through a lot of character development, but since we haven't seen ANY of it, it doesn't matter at all and therefore counts for nothing.