Best Big Bad of MLP FIM?

Who is your favorite major villain of MLP FIM, and why?
 
There’s a lot of antagonists and villains in the show, so I’ve narrowed the poll down  
to exclusively those who have featured in season premieres and/or finales, listed in order of appearance.
 
Please don’t vote anyone based on their post-reformation days (if any), this is about their villainous days.  
For example, don’t pick Nightmare Moon cause you like her reformed self, Princess Luna;  
pick Nightmare Moon because you like her from the s1 premiere and other ‘not Luna’ appearances.
 
Poll closes right before Christmas Eve.

It’s a toss-up between Chrysalis and Sombra for me. But Sombra’s only because of EU material, and while EU also makes her better Chrysalis still manages enough villain swag in the show to not need extras.
 
She came around at the right time for maximum impact as well as secrecy. Just try and pull off a twist like her nowadays and we’ll be spoiled months beforehand. Just need to listen to This Day Aria to sum up why she always hypes.

@Dustcan  
EU? Do you mean ‘AU’ as in ‘alternate universe’?  
I hope you’re not counting the reformed and/or ‘good sombra’ stuff.

@Amethyst_Crystal
 
Expanded Universe. The secondary material like the books, comics, etc.
 
And yes I do think his comic backstory and redemption arc puts him as a top tier villain.
 
But as I said Chrysalis manages to be top tier in the primary material so that puts her over.

Sombra, all the fucking way!
 
The dude managed to enslave and traumatize an entire kingdom before he got banished. He also managed to hide the Crystal Heart, the powersource of the empire and what keeps it from turning it into a frozen wasteland, in a place no one would look, all with a lot of traps and safety precautions that only a genius can solve. The best part? If it wasn’t for Spike coming along, he would’ve won and enslaved the empire again and caused a Great War judging by the Starlight bad timeline.
 
Seriously, underrated as fuck villain who is sadly only remembered for his stairs fetish which that got overshadowed by Silverstream. Damn shame… :/

@Dustcan  
Well what I meant is,  
don’t let any ‘good alt-universe’, redemption, etc stuff get in the way of your decision.  
If you’re talking about actually bad/evil stuff Sombra did in the comics that adds to his villainy, then great.
 
@ILoveMyoozik  
Honestly I sometimes wonder if bronies latched onto Sombra’s relative lack of speech (for a cartoon villain) and the stairs and crystal stuff as a way to cope with how insanely dark he was that early in the show.
 
He didn’t need to talk much cause his centuries-old cultural, psychological & social damage on the entire crystal kingdom did much of the work for him. So did his looming presence just outside the borders relentlessly trying to break through, and his many vicious magical traps that broke hearts and ruined minds, guarding the path to the one thing that could stop him.
 
I felt it was odd that so many considered the events of the ‘what if sombra won?’ future in the s5 finale such a big ‘oh shit’ moment, Sombra magically brainwashing his slaves into soldiers and the ensuing war.  
I mean, the shit he did and was doing during the s3 premiere was just as awful, just more passive and subtle, not active and in-our-faces. It’s somewhat disappointing he wasn’t taken as seriously then.

@Amethyst_Crystal  
Not sure, but to me that’s an example of a dark villain done right. For a villain who didn’t have much speech and just made noises, he was a mastermind. The closest villain we got to having a big plan like that and almost succeed was Cozy Glow, but I have to give props to the OG.

@ILoveMyoozik  
Cozy Glow and her mentor/friend Lord Tirek both get props for being manipulative mastermind types.  
Although Tirek uniquely can change between ‘villain types’ depending on his power level.
 
@Dustcan  
Meant to address this and not just jump all over Sombra talk,  
but yeah Chrysalis’ surprise reveal in s2 finale was one of the few actual surprises ever from the show,  
and it was a very epic reveal too.

Queen Chrysalis is best villain. Starlight Glimmer has a cult, sure but is she a fucking creep ass bug? No. Not as scary. The Queen (look at that title) is doing who knows what to your horse husband

I wavered for a moment between Chrysalis and Tirek (who actually felt like the single most dangerous villain in the show), but Tirek ended up looking kinda lame and ridiculous in the ending to S8, so it’s Chryssie for me.

Looking at all of these options and thinking, Cozy was soemthing else. She felt like a breath of fresh air with FiM villains. She was manipulative, cunning, and knew when to play her cards. Compared to Queen Chrysalis who did much of the same, it worked much better for Cozy because 1. She wasn’t an established character in any of the cast’s lives, and can act the way she does without suspicion Compared to Cadance!QC who acted way out of character with Twilight in her debut, Cozy went off as a confused and lonely filly who needed help in friendship. If any of the cast knew her before hand as this crude and egotisical pony, then that would have raised some eyebrows for the sudden change.
 
And 2. She didn’t act cruel to any off the characters directly, she would be very subtle in it. Like her reasoning for failing on purpose, or her bullying of the Student 6 in “What Lies Beneath” to get into their insecurities. She wasn’t outright mean, she was hiding it behind a facade of an innocently ignorant child.

Only 11 days left and I still can’t decide!
 
The only ones I can say for sure I won’t pick are Discord & the last 3 major villains.  
I mean, they’re all decent characters,  
just none of them are as cool or interesting as villains like the other 5, imo.

Took a lot of consideration, but I ultimately decided to pick Nightmare Moon.
 
Nightmare keeps making reappearances throughout the seasons in one form or another