Would That I Could/The Mechanics of Magic, Heart, and Soul

I seem to have gotten a bit hung up in terms of the Hero Souls trilogy. Nothing's coming to me, and I think I may need to spend some time away from it. I didn't even realized I needed to do that until I finished Magic, Heart, and Soul. I promptly went, "Wait, I did what?"

Comickook was right. That is the first multi-part story I've ever actually finished. Granted, it was three chapters, but still. When you find it easier to crank out three near back-to-back chapters of a brand new story than your older larger story, it's time to just stop working on the larger one for a time.

On an unrelated note, I felt I should probably explain Rainbow's existence in Magic, Heart, and Soul, as I realized I only kinda half-assed it. If you haven't read the story yet, don't read any further. BIG spoilers.

Rainbow Dash is the imaginary friend of Fluttershy, and Fluttershy and her parents were aware of this. This is why Fluttershy's parents were concerned when she mentioned Rainbow Dash. She was getting to the age where she shouldn't be having imaginary friends.

In this story, the more magic is gathered in one area, the more lax the laws of physics become. Reality becomes malleable, and limits vanish. You would think this was good, but what do you think will happen when, eventually, the magic equaled out and stabilized? Reality would come crashing back in like a tsunami, and Twilight's soul, and her magic by proxy, would have shattered violently from the rapid backlash. Hence why Celestia had her funnel it skyward, preventing the magic from gathering around Twilight.

Now, this magic that was released into the sky wasn't chaotic, but it wasn't controlled either. It was wild, and nature grasped it first before anything else. Sensing the danger, nature did what it did best; protect itself. It billowed the magic out in a shockwave, spreading it. That didn't tame the magic though. If anything, that made it more wild due to being influenced by nature.

The thing about wild magic; it is easily influenced by emotions.

When that magic came into contact with Fluttershy asshe fell from the sky, her desperate hope and belief in Rainbow Dash catalyzed it, and took a shard of her soul to give birth to the rainbow maned Pegasus. This shard was the part of Fluttershy that knew everything about her imaginary friend, including the memories of her being imaginary. So, when Rainbow Dash caught her, she truly believed Rainbow was a real pony.

Unfortunately, the soul is the collection of all that you are, and the root of all emotions. So, when Fluttershy lost that shard of herself, it was just enough to stunt her emotional stability, making it hard for her to feel any kind of heightened emotions. Not impossible, but it would require quite a severe situation before things like rage or bravery could fully manifest in her heart, even if only briefly. This led to her meek and frail personality, as fear is an emotion that needs very little prodding to show up anyways.

Finally, when Rainbow Dash died, that soul fragment instantly returned to Fluttershy, with Rainbow Dash's own experience along for the ride. This influx of intense emotions and the sudden ability to feel her emotions fully again led to Fluttershy snapping briefly, and then completely falling to pieces as sadness overwhelmed her. Rainbow Dash reappearing and then disappearing again only strengthened that sadness.

Well, there you go. Hope that helped.