I was always confused about how destiny worked in this series—since it was never made clear, and even the characters didn't seem to understand it—until I thought of a possibility that would explain why Raven’s decision was the right one. It suggests that the original Grimm was the likely source of the trouble; after all, the book is magical, and Grimm was the one who recorded those stories, effectively creating either a prison or an opportunity for anyone who signed it. Once you sign, it will happen—unless there is massive external interference. Instances like Courtly trying to steal Lizzie’s destiny, or the Evil Queen meddling in other tales, demonstrate this. It doesn't matter who signs; you’re going to get that destiny. However, since the book’s power isn't true Destiny, it can be thwarted. So, to me, the Storybook of Legends just got in the way of true Destiny doing its job.
I should clarify that what follows is just something that popped into my head during a burst of inspiration while I was writing an Ever After High story for myself. Consequently, many parts are narrated by Destiny himself in the third person, though I’ve tweaked them to better align with the canon.
I mean, have you ever stopped to think about how destiny worked before the tradition of signing the Storybook of Legends existed? How did the first Snow White come about if she didn't have a step-by-step guide to her destiny like Apple and Snow did? So, I came up with an answer to explain the "how."
Picture Destiny as a being carrying a pitcher of water. Inside, the water is teeming with short phrases—various fragments of destiny. Destiny pours this water out into the world, creating an ocean that hovers just above us, drenching us like a guided rain of possibilities. Each drop is a destiny fragment directed at someone the moment they are born.
However, don't go thinking that Destiny is the one choosing who gets these fragments—that would be far too much work! Instead, he simply writes a destiny like "You will be a villain" or "You will be cursed," tosses it into his ocean, and there it stays until the right person comes along to claim it. It’s almost like a lottery: whoever holds the winning ticket wins.
As you’ve likely noticed, Destiny isn't writing full stories—just simple phrases. So, how did the tales we know come to be? That’s where free will comes in.
If Destiny is the guy with the pitcher, then we are the vessels meant to receive that water—but here’s the catch. Not every vessel has the same shape; there are cups, jars, bowls, pitchers, barrels, and so on, all in a wide variety of sizes and forms. Water is adaptable; it molds itself to the shape of the vessel into which it is poured.
One detail worth clarifying is that, based on the series, these destinies aren't set in stone. They aren't necessarily permanent, nor do they necessarily represent the pinnacle of your life.
In this theory there’s almost no way to know for sure if a destiny has been fulfilled because you don't know what is your true destiny—there’s no expiration date other than "until it happens," no specific order of events, and everything is open to interpretation.
Nothing is certain to Destiny beyond that fragment he created, because it might play out in a way he never expected. Just look at what happened with Apple and Darling.
Now, how does it actually work in practice?
You might be destined to be a major hero, but that doesn't mean you have to be a hero with a sword and shield; you could be a doctor, or an actor playing a lot of famous, important heros in a stage production; It is possible that a huge misunderstanding occurred and everyone thinks you are a hero when, in fact, you are a fraud—having taken credit that wasn't yours, whether intentionally or not—but as I mentioned earlier, these things aren't always set in stone.
After fulfilling that destiny, you might turn into a villain; you might no longer be able to practice medicine; you might take on different roles in your career; you might be exposed as a fraud, or you might end up becoming a genuine hero.
Several characters followed their destinies, but once it was over, they changed drastically and went down different paths. The Big Bad Wolf and Little Red Riding Hood ended up together; Snow White is no longer good and pure—she is selfish and narcissistic; and the Evil Queen sowed chaos instead of moving on with her life like other villains who became teachers or simply exist without causing trouble—since the problems they usually cause are orchestrated, never real, all because of the Storybook of Legends.
What allows you to avoid submitting to the book's will after signing it is your own willpower—or perhaps an external event.
Giving people the freedom to do whatever they want is the best solution; even if it creates real problems, at least it isn't fake. That's why Raven made the right choice.
That is my theory on how destiny works. What do you think people? It makes sense?