Oh his sister got the disease too? Boy that shown so bad in the webtoon if it's true, are you guys sure it's not a bad translation? First he thinks se got a trauma from the monster attack and by the end "I have to choose"???? wth
(btw this isn't a spoiler because i haven't read the novel, i am just a webtoon reader concluding this from this bad "I have to choose" ending)