On King Sombra
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To quote brawlmaster012, a wise Youtuber.

"People are really missing the point of Sombra's character. Sombra is NOT like Nightmare Moon, Discord, or Queen Chrysalis. He doesn't have a physical form thanks to Celestia and Luna so a direct confrontation would be impossible. His only purpose is as an indirect threat, thus prompting an indirect solution aka the retrieval of the Crystal Heart instead of a battle like so many people seem to have expected. Honestly, if this guy was just another Queen Chrysalis, this episode would've bored me."

I kinda have to agree with that, after all King Sombra didn't really become physical until he almost had the Crystal Heart which is probably why he didn't attack anyone. Although he did display the ability to use magic so there could have been a magic fight or something, oh well. Too bad he was blown to bits shortly after becoming whole again.

Plus if you look at him just before he cries out, you'll see that he looks sad, like he's sad to see all that waiting and struggle just to get his body and empire back go to waste after such a short amount of time.