Brandon Sanderson's short fiction is known for its rich world - building. His stories often feature unique magic systems. For example, in some of his works, magic is based on strict rules and limitations, which makes it feel more like a science in a way. This adds a sense of realism to the fantastical elements.
I'm not sure specifically which four novels are being referred to as 'secret' by Brandon Sanderson. He has a large body of work, and perhaps these are upcoming projects not yet fully revealed.
Brandon Sanderson's 'Elantris' is a great magic novel too. It has a unique magic system that has been corrupted in the story, and the characters' relationship with this magic is an important part of the plot. The way he builds the world around the magic is truly remarkable.
One of the things that makes it unique is his creativity in creating magic systems. It's not just about waving a wand and making things happen. There are costs and consequences to using magic in his stories.
The word count in a Brandon Sanderson novel can differ greatly. On average, they tend to be in the range of 120,000 to 150,000 words. But some of his epic fantasies might exceed that.
Brandon Sanderson usually starts with a core concept or a unique magic system and builds the plot around it. He often plans out the major plot points in advance but leaves room for flexibility and character-driven developments.
Brandon Sanderson has written a substantial number of novels. His works include popular series like The Stormlight Archive and Mistborn. To be precise, it's a constantly growing number as he continues to create new stories.