The suspected changeling spy will be the same one who attended Cranky and Matilda's wedding.
Nope, it's a different changeling altogther.
However wrong they are in their prejudice from a ethical and moral standpoint, after what they were subjected to in the events of A Canterlot Wedding, Shining Armor and Cadance can hardly be blamed for not liking, let alone trusting changelings. In fact, after all of the hell that Queen Chrysalis put them through, it would be no surprise that Cadance and Shining Armor have PTSD and thus have every right to fear changelings.
However, this troper fears this episode will not aim to treat them as either justified or sympathetic. That Shining especially is going to instead be painted as a one-note, racist 'authority jerk' to serve as the designated antagonist to Spike and the changeling, probably alongside Twilight, until they are enlightened by episodes end.
This is mainly due to how the audience's sympathy and support is likely to be with Spike and the changeling, which will be made all the easier if the writers make the opposing side almost entirely unsympathetic and treating them as if they have no leg to stand on. Strawmanning a main character for the purpose of a moral is a common practice in most forms of media, Friendship Is Magic being no exception.
- Cadance and Shining Armor are afraid of Thorax at first, but Spike quickly wins them over, thanks to Twilight being the first to accept Thorax, offering her hoof in friendship, and that convinces her sister-in-law and B.B.B.F.F. to do the same, helping them overcome their prejudice of changelings.
The changeling is a spy, but he betrayed Queen Chrysalis.
If the changeling is actually a spy, he probably went rogue after getting to the Crystal Empire. He was sent to kidnap Princess Flurry Heart and replace her with a changeling baby to feed off their love as part of the Queen's revenge plan, but he only used it as an opportunity to escape the abuses of the Queen. So he decides to stay in the Crystal Empire in hopes of starting over.
- Sort of. Apparently, Thorax was never as evil as his fellow changelings, and he left them during the battle at Canterlot. He doesn't live in the Crystal Empire; instead, he's hiding in the frozen wastes outside the Empire.
Queen Chrysalis will make a cameo.
She will not be seen directly, but perhaps as a looming threat in the distance. She will declare the changeling a traitor to his people and swear revenge on Cadence and Shining Armor. This will serve as a Sequel Hook
for her official return, perhaps in the next season.
- She appears briefly in a flashback and has no dialogue.
We'll finally find out what became of Chrysalis and the rest of the changelings following their defeat in Canterlot.
Outside of the IDW comics, which are not considered part of the official FiM canon, we haven't heard anything about what became of Chrysalis following her failed invasion of Canterlot back in season 2.
- She and the changelings are most likely somewhere on the outskirts of Equestria and are starving to death without love to feed. Chrysalis will have a burning hatred for Cadence and Shining Armor, and is planning to feed off the love radiating from the Crystal Heart. Her hatred will have driven her to the point where she abuses her subjects for having failed her in Canterlot, and now she plans to use the Crystal Heart's power to destroy Cadence and Shining Armor.
- Jossed. All we see of Chrysalis or the other changelings is in the flashbacks.
This episode will reveal that Shining Armor considers A Canterlot Wedding
to be My Greatest Failure
It makes sense if it turns out to be; he was totally fooled by Chrysalis, tricked into near irreparably falling out with his sister, his real fiancé was trapped down in the caves for who-knows-how-long, gotten brainwashed by "headache spells" and because of all that Canterlot and his family was nearly destroyed. The guilt from knowing that he was mostly responible for the Changeling Queen's Near-Villain Victory
has to take a serious toll on his mental health.
- Could also explain why he always cries at weddings.
- Jossed; it's not mentioned at all, but his and Cadance's initial hostility towards Thorax is caused by what had happened during the events of the Wedding.
The changeling belongs to a different Hive.
All of the changelings of Hive Chrysalis have a Navy Blue
Dorsal Carapace. So why does this one have a Teal Green
Dorsal Carapace? Could it actually be possible that Chrysalis isn't the only changeling Queen in existence and that the changeling species is so much more numerous than originally believed that there is actually more than one Hive in the world of MLP:FiM?
- Averted in that Thorax says he was "raised by an evil queen" and a flashback in the episode shows that he was indeed part of Chrysalis's hive and was even (reluctantly) part of the Canterlot invasion force.
There will be a scene where Flurry Heart hugs the changeling.
- No such luck, but we do get two scenes of her making goo-goo eyes at him.
There is a changeling Refugee crisis
Thorax's name is actually 4-X
Chrysalis doesn't seem like the type to give each changeling a proper name. It's possible that Thorax was originally just given an identifier of "4-X", which just happens to sound like the word "Thorax".
Thorax actually was a spy, but went native.
He actually was sent to the Crystal Empire to spy on Cadance and/or Flurry Heart, but he took a liking to the ponies and eventually stopped reporting back in to Chrysalis.
Chrysalis will invade the Crystal Empire under the pretext that Thorax has been captured
Thinking the ponies have imprisoned Thorax, Chrysalis will launch an invasion. Seeing that Thorax had befriended the ponies may lead to peace with the hive. Or...
Some, or most, of the changelings will follow Thorax's example, but Chrysalis will not
Thorax has no love for Chrysalis and openly refers to her as an "evil queen." This could be a hint that Chrysalis is too far gone to be reformed and may have to be destroyed.
Why is Thorax different than all the others. Genetic mutation of some sort, or is he somehow part pony?
Thorax may never leave the Crystal Empire?
The Crystal Empire is the only safe place that Thorax can live in without doing harm to others and starving from lack of love. He may become too attached to his new home and friends to go and share the knowledge of friendship with other changelings.
Thorax will incite a Civil War?
Thorax is on his way to becoming the first and founding member of an Anti-Chrysalis Group if he really intends to share the knowledge of friendship with other changelings and succeeds in convincing some of them to abandon the evil ways of Queen Chrysalis.
Thorax will be captured by Queen Chrysalis?
Thorax might put himself in danger if he goes back to the changeling Kingdom which will most likely greet him with a hostile reception and force Queen Chrysalis to denounce Thorax as a traitor to his species. She will then use Thorax as bait to lure in Spike and the Mane Six who have no choice but to try and rescue Thorax.
A class of Nobility exists in the Changeling Hierarchy?
Thorax's statement that he was raised by an evil Queen is an implication that there is more than one Queen in the changeling Kingdom or at least a confirmation to the existence of Proto-Queens in the species.
Queen Chrysalis will secretly exploit Thorax?
Queen Chrysalis will get word of Thorax's betrayal but capitalize on his naievety and plans to share Friendship with the changelings by having him unwittingly bring spies hidden among the changelings that choose to follow Thorax back into the Crystal Empire.
Possible friendship problems between Thorax and the rest of the Mane Six?
1. Because Rainbow Dash dreams about fighting changelings in "Do Princesses Dream of Magic Sheep?", she might be the least receptive of the mane six about accepting Thorax as a friend. The possible reasons for her dream are petty revenge for being captured in A Canterlot Wedding and the thrill of using physical force against changelings.
2. Applejack might also be the second most resistant of the mane six about accepting Thorax, adopting a suspicious stance against the changeling if they meet for the first time and believing that he's hiding an ulterior motive underneath a very convincing act of open friendliness.
3. Fluttershy will most likely be terrified of meeting Thorax for the first time and will run away or barricade herself inside her house but will be quick to accept him if Twilight convinces her that he's harmless.
4. Rarity's possible problems are trying not to be rude enough to point out how unsettling Thorax's appearance is and trying to make some clothing that would look nice enough on a changeling, provided that Rarity can find some common ground with Thorax's sense of fashion (or lack thereof).
5. Pinkie's possible problem is not knowing anything about changeling culture or dietary habits to throw a party that Thorax would like. A worst-case scenario would be Pinkie serving up something that would make Thorax sick when he eats it.