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.
It's hard to say for sure. The decision to turn a manhwa into anime involves multiple considerations such as the story's appeal, available resources, and market demand. Sometimes it happens, but not always.
I'm not sure specifically as there could be many novels with such a title. Generally, it might be about a character who makes a pact with the devil, perhaps in exchange for power, wealth, or to achieve some impossible goal. This often leads to a series of events where the character has to face the consequences of their deal, like moral dilemmas and unforeseen challenges.
I'm not sure who the author of the 'i made a deal with the devil novel' is. There could be many self - published or relatively unknown authors with a novel by this name.
It really depends. I need to carefully review the details of the contract first. Things like rights, obligations, and potential benefits all matter before I make a decision.