Hard to tell without reading. It could be a new challenge for the main character, a reveal of a secret, or the advancement of a subplot. You'll just have to check it out yourself to know for sure.
Sorry, I haven't read that chapter, so I can't give you a definite answer. But usually, chapters in manhwas bring new developments and keep the story moving forward in interesting ways.
I don't know for sure. It could involve the development of the main character's story arc or a key event that drives the plot forward. Try looking for fan-made summaries or reviews to get an idea.