Greetings!

Down below will be prompts for your Devil's Advocate Session. Please comment inline on any suggestion of mine you would like to dive deeper into, and I will reply as soon as possible. You are not forced to take any of these suggestions. I only wrote about what I thought was necessary.  

Character Development-- As you only have a few chapters so far, it is hard to see how this will develop. However, I encourage you to focus on a few base personality traits for Rivule, specifically. 

I already have a burning passion to murder her mother, but what drives her? Seeing as she is one of your main characters and (I assume) the protagonist, I would love to help find some way for her to follow her goals yet keep whatever personality traits you've designated for the princess. Breaking character is one of the best ways to signal: 'Hey, something is not right and this is where everything starts happening' to your reader, and keeping some base character traits consistent signals this even louder.

Grammar/Spelling--Spelling is perfect. Grammar is also satisfactory, although you may want to straighten some phrases out. Try reading your chapters out loud and see if they sound clunky. I can point you to some examples if you'd like. 

Word Choice--You have incorporated a huge variety of word choice into your writing, and I know that this is not always easy to do. However, I suggest that you really dive deep into where the words that you are using should be used, and in what context. Otherwise, some really beautiful word choice could mar your clarity and make it difficult to read. Harry Potter is a fun read for all ages, and the word choice is many of the reasons why. It is professional but also simplistic, enough so that context clues can help unknown words click for the reader.

Style--I personally love the little poem-like starters at the start of each chapter. They really add a personal flourish and some food for thought. As long as you make sure that these little preludes are completely relevant, it adds a lot to your style. You could even use them for a tad bit of foreshadowing.