Okay, I know that the title sounds a little harsh, but, I do wonder. Could Twilight, possibly unknowingly, have some sort of control over Spike?

This is based off a video reading I listened to on youtube by Historical Equestria, so, if you haven't seen it, be warned, spoilers ahead.

So, watching the seventh and final volume in the series, according to the head canon, Spike was once Bahamut, self-proclaimed king of all the dragons. His size was unmatched by any of his kind, as was his greed. The only one to rival him was his sister Tarask. According to the Canterlot archives, a soul stone from Tarask's horde was placed in Luna's crown that would capture the spirit of who soever donned the crown. When he donned the crown on his finger, his greed was taken from him and his size with it. What's more, he would be compelled to serve whoever possessed the soul stone.

Seeing as how he seems to bare an unbreakable loyalty to the princess of friendship, this makes me feel that there are four possible reasons for why this is:

1. Seeing as how Luna has not received an undying servitude from the Baby Dragon, we can assume the soul stone is no longer one with her crown, or we may have had two souls in one stone. So, this must mean that Celestia gave Twilight the soul stone, all though, she was not told of this, and the knowledge was best kept secret so that Twilight would not use this knowledge for selfish means, even if they were for the best intentions of Equestria.

2. The stone was split carefully by Celestia's magic into three pieces, one, holding Bahumut's soul itself, one holding his immense size, and another holding his greed, and the one piece that contained his soul was fed to him, so that he would not stay a hatchling forever.

3. Somehow, possibly through unintentional means of Twilight's parents, Twilight Sparkle was herself was an embodiment of the stone, making her the only one capable of freeing Spike/Bahamut from his egg prison, and thus why her magic outdoes any unicorn or alicorn, aside from her niece. (This theory is the least likely.)

4. Somewhat like the second theory, Celestia had separated the stone into smaller fragments, and the pieces this time had been purposely scattered by her, so that Spike/Bahamut would not become his evil self once more. It is possible that Twilight may have found part of the stone, and kept it for research for not knowing what it was, and wanting to find out more about it, or that Celestia had kept a piece which contained Spike's Spirit without the greed, magic and size as well, and Twilight kept it close as a memento from her teacher, and thus Spike is eternally bound to Twilight.

Now with theories 2 and 4, there's a part where Rarity comes into play. Being as she is great at finding gems for her fashion creation, it is possible she may have stumbled upon a fragment of the Soul Stone, and, seeing how it was so rare to find such a gem, she kept it close to her for more inspiration. This could explain why Spike has a crush on Rarity, and both could, unintentionally, be tracking more fragments of Spike's former Bahamut self.

This is of course only based on the head canon, but what do you think? Let me know in the comments below of why Spike never really swerves in his devotion to Twilight, even when he does have his childish rebel side to him.

The number 2 idea sounds good

The number 2 idea sounds good