@Background Pony #8957  
Additionally, could villains be friends without having to be good guys themselves?  
Friendship in this show is portrayed as a force of the Light Side, but to me it still could easily be a force of the Dark Side. It is shown to be magic yes, but it’s still just that, magic. Not “Pure” not “Heroic” just “magic”

@nightshroud96  
True that, it’s just that, what if they conspire another plan?  
And as for the whole “powerless” thing, consider this  
Could Tirek drain Cerberus’s Magic?  
It would both grant him strength and knock out Tartarus’s only guard

@Background Pony #8957  
That is if someone tried.  
Never hurts to try.
 
The trio shown signs of changing in Frenemies until Chrysalis(who is not in the right state of mind pretty much, like she needs help there) snapped them out of it. If effort is put into it, then it is possible for them to change.

@Background Pony #8957  
Tarturus at least the prisoners can still talk to someone and move and think. They won’t be able to get out(obviously the flaws that let Tirek escape would be fixed) since they are just powerless and someone could at least see them.  
Not sure what is it like for those in Limbo and there’s confusion on what happens to NMM while she’s at the moon.

@nightshroud96  
And as for you, the punishment system in Equestria is diverse  
Moon  
Stone  
Limbo  
Tartarus  
But the last one has appeared twice  
And if you’re going to do that, you might as well make other punishments reappear to

@nightshroud96  
Who said anything about changing them?  
It’s clear they’re not going to come around no matter what.

@Background Pony #8957  
It would be better if the trio were just in Tarturus and awake.  
So they would just bicker at each other and thats it. No longer threats and only got each other.  
And they MIGHT change there. They might not.  
Having them be on “pause” like that is not going to change them at all.  
They shouldn’t be stuck a fate worse than death with being a statue(not being “awake” doesn’t make it any less of a fate worse than death).

@Background Pony #8957  
Oh? How so?

@Background Pony #8957  
Still, I feel the stone sleep thing felt appropriate, as well as a nice continuity nod

plus Cerberus hasn’t left his post for at least a thousand years, so it’ll be a while before that happens again

@Background Pony #8957  
Pretty much they would have learned from that flaw that allowed Tirek to escape.  
Clearly they would have added something in just in-case Cerberus leaves its post again.

@Background Pony #8957  
I’m sure that he’s gone through better guard dog training after that.

@Smart Heart  
But what if Cerberus leaves his post again?

@Background Pony #8957  
Put them back in Tartarus then.

@Smart Heart  
But it’s better than leaving to cause more trouble in the long run, now is it?

@Background Pony #8957  
But you can’t just leave them like that.

Well to be fair, Discord’s idea WAS indeed fitting

I think why the sisters listened to him is the fact they were too pissed to realized he shouldn’t be allowed to decide the Trio’s fates like that with its ultimately his fault there.  
Luna and Celestia ended up “failing” once again(no, distracting the trio doesn’t fix that) on their very last days as rulers. And the fact salt got rubbed in the wound about them no longer being connected to the Elements with they weren’t included in the final rainbow despite they wielded the Elements before and their cutie marks were on the damn tree of harmony. Pretty much it rubbed in the fact destiny ultimately tossed Luna and Celestia aside.  
The sisters were too blinded by their rage from all of this to realize that Discord shouldn’t been allowed to decide the fates of the villains he caused to be threats again and were going to use as cannon fodder for Twilight.

@AC97  
Pretty sure they wouldn’t though.  
Most likely just beating them up a bit and send them to Tarturus and that’s it.  
Even if they wanted to, I don’t think the sisters(especially Celestia) can bring themselves to horribly kill someone like that. Especially infront of the whole world like that.

@PastelBacon  
The Royal Sisters are done dirty in this finale too honestly..

@Background Pony #298  
Yah, discord really needs to be locked in something like scp-2701 for a month or 2(outside time), come to think of it that would also be a great punishment for Cozy, tired, and chrysalis, except with them I’d set it for a few years

@Prometheus labs CEO  
For Tirek, sure. Not so much for a non super powered Chryssie, who isn’t particularly dangerous on her own, without her hive. And I’m not sure how in the name of fuck you’d justify that logic for a what is essentially a missguided kid with no special powers what so ever.  
Hell. Cozy and Tirek where already safely contained until Discord broke them out and until Discord pointed them at an ancient artifact of extreme power, only Tirek was capable of posing a real threat to Equestria.  
The problem isn’t how inherently dangerous they are, its how dangerous Discord made them.

@Prometheus labs CEO  
So, murder execution, then?

@Prometheus labs CEO  
And if they somehow get released again?

@UserAccount  
I’m pretty sure it was just meant to be a measure to prevent them from posing a threat again. chrysalis, Tirek, and Cozy glow have all proven to be very dangerous, and are the kind of villains that just keep coming back, so what better punishment than one that makes it virtually impossible for them to come back or otherwise pose a threat to her people ever again.