Waldo here, and let me explain what that title means.

Sombra is, undoubtedly, the best villain in the show. He's definitely the most inherently malicious, and had he gotten more screen time I know he would have been undoubtedly much more popular.

But as it is, he's still a cool character. Why? Because nobody knows what really happened to him! There's so many possibilities that might have led to the gem-obsessed fucked up King we all know and love!

And it is one of these options that I take. it's relatively generic, a former captain of the Crystal Guard, but what if the evil he had was like the Venom symbiote, what if it could find a new host? What if it was so powerful it could send Sombra into the future upon death, to find a new pony to feed off of?

And what if Sombra had something to say about that?

Hmm... Sombra is a shadow, after all. What does a shadow fear?

Love. Because love is the brightest hope there is.

Thus, I present to What A Shadow Fears, a look at the above possibility. Let's see just how twisted Sombra could have been, shall we?

Waldo, out.

2769529 Well, I guess I got another story to read, eh.

2769529 Well, according to the wikia and some trading cards, they say that his horn had survived, and they said he is due for an appearance in the upcoming comics, so chances are, we might see him again in the future in the show.

And I agree, Sombra would had been loved by the masses if only he had more dialogue and more work was put into him. Unlike all the hate Flash gets for his 'one-sided characterness', the hate Sombra got was understandable, but would had been prevented if things were different.

Hey, at least his lack of a background leaves a lot to the imagination, right?

In my personal headcanon, Sombra is the product of, as Waldo suggested, an entity that bonded with the king of the original Crystal Empire. It preyed on his desire for control, having lost the chance to be with his lover, the Equestrian princess Luna. He only had his daughter Cadance to comfort him, and it made him vulnerable to the parasite. At first, it gave him what he wanted: the ability to control his subjects, and with the parasite influencing his mind, he couldn't see the fear in the eyes of his ponies. When his vile actions became such an atrocity to Celestia that she asked Luna to help cut off the city from the rest of the world, Luna's desire to help her former lover. She redirects the spell that they cast on the city, and instead of leaving it there, she removes it from their plane of existence and puts it into a pocket dimension.
Then it reappears. Did anyone else notice how Luna reacted to the news?

The main character would have simply wiped out him out with a SHAZAM if Cadance hadn't asked him to use his famous ability in doing the impossible to save her father, which he did at the expense of the city. That got blown up.

I say he never took over the empire he just wanted to make it stronger incase of war and ended up using dark or forbidden magic and ended up corrupted.

I agree with Dark Bane to a certain point, because in the end he did take over the empire, the saying "the road to hell is filled with good intentions" fits him perfectly, Sombra paid the ultimate price by messing with forces far being his control, and that good and once noble pony he was is now gone, replaced by an twisted version of himself.