Well if you want it that way then we need to do something else and Sunset shimmer an alicorn.🌞🌚🌞🌚

Maybe this is what happened, and Sunset’s mental decay and toxic influence during her time in Equestria made Garble into the violent pony hating thug he is now.

@CronoM
 
It’d have made for a nice bit of character work if it happened.

Wow, this is a seriously awesome headcanon. The way Garble is drawn here in comparison to Spike makes me almost think this is actually from the show.
 
I’m starting to imagine a Season 6 episode where Sunset Shimmer hears about Garble from Spike, and Sunset Shimmer wants to find him and mend their relationship.
 
When she sets out to find him(along with Spike and some of the others maybe) at a small migration site, Garble’s really shocked to see Sunset; its obvious they have their issues, but its also obvious he still cares for her and he hides Sunset whenever his rowdy dragon friends get close, on the pretense that he doesn’t want them to know that he was once friends with a pony, but in reality he just doesn’t want Sunset to get hurt.
 
Garble is very confrontational about coming back with Sunset, says he cares a lot about his rep. here with the other dragons cause they see him as tough. But Sunset insists that, like herself, Garble used to be a lot deeper then that…while he wasn’t a pure of heart hero-type like Spike, he always dreamed of being the first dragon Captain of the Guards of Canterlot…mostly because nobody beyond Sunset expected anything from an ill-tempered red fire dragon like Garble but trouble. (+10 extra points if it shows a flashback of young Garble making a very bad impression on a younger Miss Harshwhinny)
 
When Garble’s friends finally find Sunset and the others, and think Garble just ‘found’ them to beat up, Garble hesitates and finally stands between them, saying he’ll stand by the friends that really respect him. Maybe even have Garble, Sunset and Spike do some fire magic combination that singes the bullies scared. Garble doesn’t do a complete 180, he’s still overly macho and quite a troublemaker, but he’s still protective and a good foil for Spike and a good little brother figure and confidant to Sunset.

This is by far one of the best sunset shimmer headcanons I’ve seen in a while

G: Who’s up for a belching contest!?  
SS: He didn’t learn that from me, I swear.

Oh, he’s Garble? I thought he was Reginald.

That explains everything.

I’m not going to incorporate this into my own headcanon (I have my own theory), but it’s a neat idea.

Hey, that was my idea.
 
And I still like it.

HEADCANONED!