@Zincy
A good reason why it needs to be banned forever.

How did that work out for you, Twily?

The “Princess of Friendship” isn’t being so friendly here, is she?

Result.
 
And Chrysalis got her hives dominated half of Equestria by that time of that image.

@UltraVaderMan  
“Enough of your madness…if you must be stopped…so be it”
 
Twilight’s eyes widen
 
“This…this has happened before…”

@Background Pony #4495  
“Do not force my hoof, Spike!”
 
Spike groans from the fight
 
“The kingdom and the timeline hang in the balance! To defend them, I MUST COMMAND ORDER!”
 
“I thought it impossible…but Starlight was right, you cannot be trusted!”
 
“I DO NOT NEED TRUST! I DEMAND OBEDIENCE!” Dark magic flares out of her horn and her eyes turn evil

“This is not the way! Starlight is not the enemy this time!”
 
“SPIKE! DO NOT INTERFERE!”
 
Que MK11 fight

@Xonxt
 
Okay, let’s say they dethroned Chrysalis somehow, dealt with the Pony of Shadows without Starlight, possibly no Stygian redemption there (less forgiving Twilight, after all), whatever, then you’d have a world where Starlight and Tirek were yanked right out of Tartarus by Grogar, to be… persuaded into working for him.
 
And the aforementioned possible lack of Pony of Shadows redemption would possibly be something Grogar could use, too.
 
Depending on how you’d have the divergence course set up, maybe Cozy Glow would still end up on that team, or not.
 
Maybe such a change of events would turn out interesting.
 
Point is though, it’s probably not a matter of if this alternate choice would backfire, but when.

@Xonxt  
Obviously she is.

@genervt  
not necessarily. Because in this “verse” Twilight is not an idiot.

@Background Pony #D358  
Which is exactly what happened to Cozy Glow. LOL!

And Chrysalis rules Equestria.

Everything with sentence ok-exept sending her next to Tirek

Everything good with sentence- exept sending her next to Tirek

Congratulations. You’ve allowed Starlight to collaborate with Lord Tirek. That magical suppression device will only work for so long.

@Background Pony #3B76  

 
 
Basically my response to your proposition is this video

You know what i would have done? Snap her neck. No second thought.

I can see why this is a bad end. Because by the time Starlight is finally out of Tartarus after 1000 moons(I still don’t get why ponies don’t just say years), she and Tirek will take over Equestria again. That is why this is a bad end.

@Crystal Neighybánya  
Oh of course. That’s where a great judgement comes in - the “they’re very good at “feeling out” the situation. If that always leads them right” part. They’d know this guy isn’t coming around, and he’d be in Tartarus forever - or until his death, since he’s mortal.

@Cirrus Light  
Aside from the concerns you brought up, there’s also the fact there are some people who can’t be reformed or refuse to be reformed. I doubt a man like Hideki Tojo would bother listening to someone lecturing him on the value of human rights and political pluralism, even if you’d let him off the hook. That’s the nice thing about fiction: you can create outcomes that can never happen in real life.

This is actually a reason I love the Equestrian ruling class. Some people can just tell when someone’s being sincere or lying - they’re very good at “feeling out” the situation. If that always leads them right, and they have supreme authority, then they can let people go scott-free for things if they’re truly repentant of them, and if they’ve learned their lesson. In such situations, rather than make a powerful enemy and someone who gets trapped in the system of “Prison” -> “Can’t get a job because criminal background, so do crime to survive” -> “Prison” -> etc, they can skip all the unnecessary evil that is inflicted.
 
Sadly, it’s not something that could ever work in the real world, though… 1. Who would you pick? Anyone who comes forward is almost certainly doing it for the wrong reasons and would be a terrible supreme ruler. Any random person isn’t going to be much better. 2. When they die, you have to do 1. again until you inevitably get someone who’s terrible.
 
Equestria got around the problem with Celestia, though…
 
What we need is a Lobster-king :q (Lobsters are immortal, fun fact - they’re very killable, of course, but don’t “die of old age”) (Okay, reading about it, not really immortal because of molting stuff, but put those genetic properties in a mammal and they probably would be?)

This should have a good end tag. It’s a good end because it’s realistic.

@whitestar60  
You took the words out of my mouth. There were so many potential stories and avenues for development that got shut down thanks to that montage.

@whitestar60  
In the Season 3 finale, Twilight did a spiral flight pattern to the camera, but the next season opened with her barely being able to fly.
 
I’m hoping this might be similar?
 
I still need to see the first minute of the new episode.

@Mr grump  
Don’t forget she then spent the whole of Rainbow Rocks being hated by almost all of CHS, and even the Rainbooms didn’t completely trust her, Hell even Twilight was hesitant.  
Then Starlight gets forgiven by Everypony in a montage. that more than the Unicorn beating the element of MAGIC or anything else in that finale pisses me off. All the wasted story potential, Starlight winning over each of the main six could have been it’s own episode. the Equal village? a two parter. Hell maybe they could finally do the moral they’ve been dancing around since Discord, “That sometimes forgiving someone, especially someone who hurt you deeply is the hardest thing you can do.”