To survive, you should build alliances with the right characters. Also, stay away from obvious traps and don't trust everyone easily. Keep a low profile when necessary.
The devil in manhwa can take many forms. It could be a traditional evil character with horns and a pitchfork, or it could be a more symbolic representation of evil or temptation. It all comes down to the imagination of the author and the message they want to convey through the story.
A daughter-in-law manhwa often focuses on family dynamics and the relationship between the daughter-in-law and the rest of the family. It might have elements of drama, romance, and sometimes comedy.
It could be due to a series of unexpected events and circumstances that led to your character's transformation. Maybe there was a prophecy or a hidden heritage.