I actually really like this, just sorta seems like the brother has a sister complex which is sorta weird. But it's still good continue updating (>'o'>) I recommend this the art is good, and the plot is interesting. I personally like strong FL's but it's whatever.
The art style suits the theme of this webtoon, but it's not particularly great. So far, the female lead who can see the death countdown has been unable to stop it completely. I think that's a good thing, to watch her struggle with her powers and her own helplessness. Her brother is underused so far, I'm not sure if he is evil or just conveniently there when needed.