@JP  
Considering what happened to the Joker when The Spectre did something similar…probably not too well.
 
The Spectre tried to pass judgement on Joker. Couldn’t, because Joker is legitimately insane and thus not responsible for his actions on the level Spectre (the incarnation of God’s Vengeance-Sodom and Gomorrah, the Ten Plagues, etc) operates on. So instead, Joker was given temporary sanity.
 
TL;DR, it just made him worse afterwards, iirc.

@Phantom Rider  

 
I think the implication is that it’s the Elements/Rainbow of Harmony that is the Penance Stare. It’s a bit of fanon I’ve seen discussed a few times before, and it’s a bit I have taken as Headcanon myself.

I wonder how the other two are doing  
At changedling hive  
Chrysalis: crying hysterically I’m sorry my son! I’m so sorry! collapses into thorax’s Shoulder  
Thorax: mom, this is the 10th time this week, how many times do I have to say that I forgive you?
 
In another room of the castle  
Tirek: IT HURTS IT HURTS MAKE IT STOP!! starts ripping pieces of his hair out SOMEONE KILL ME!!

Twilight has the Penance Stare?

@Background Pony #F329  
That statement says frightening things about human nature…do you really think we’re that bad?

Twilight: “Starlight you really think it’s okay to be drugging cocoa.”  
Starlight: “What? Drugging cocoa? Don’t be silly Twilight…now the marshmallows…is a different story…”

@Otterhand  
“I see…”

@Ereiam  
Cozy: “This Coco taste weird…”  
Starlight: “That’s the taste of “empathy” Cozy.”

@AzriBoss  
Maybe like Otterhand suggested:  

How could this happen?

Your tears are delicious.

Twilight: No! but i will help you to be finaly a good pony and when you finaly learn, Your pain is will be over!

@Background Pony #D6FE  
Perhaps the more accurate wording would be remorse… she definitely didn’t feel any of it. I mean she saw other ponies as tools to be used to advance her own agenda, namely taking over the world, and didn’t bat an eye at . And there’s a difference between kids being brats and a kid who is incapable of caring about the well-being of others on anything but a superficial level. It’s the difference between “This kid is out of control” and “this kid acts all sweet but he’s single-handedly responsible for why the family pet “disappeared” every time they got a new one.”
 
And actually some people can feel some degree of empathy even if they haven’t experienced it first hand… that’s kind of the definition. According to Webster’s dictionary: “The action of understanding, being aware of, being sensitive to, and vicariously experiencing the feelings, thoughts, and experience of another of either the past or present without having the feelings, thoughts, and experience fully communicated in an objectively explicit manner.” It’s not the same as what they’re feeling, but it’s something.

@RBD49  
Empathy, what is this empathy you speak of? Cozy Glow doesnt feel empathy becuz she is more “human” than most characters. Really, she is just your typical average evil lil demonic child, of which most children are almost literal devils anyway. ALso, on the topic of empathy, it is impossible to feel any form of synpathy/empathy for anyone unless you experience for yourself whatever horrible thing happened to them.

I mean, she (Cozy Glow) is the quintessential “This kid’s growing up to be a serial killer” character. If she weren’t a minor she’d have Antisocial Personality Disorder. Like them, it’s evident Cozy Glow never felt remorse or empathy for what her actions did to ponies. Making her feel empathy like that… after never having felt it before, and knowing all she did… that would be overwhelming. This reaction, I think it’s pretty accurate to how that must feel.

Damn. I wonder how Tirek and Chrysalis are fairing with this?

@Digital Seapony  

 
I thought of Spongebob, myself, but your’s is better.
 
“Need…hatred!”

Either Twilight forces her to feel emphaty or she starts develloping it on her own. In the laters case it’s more natural she’s scared. Cause it’s an emotion she never feelt before and it’s eating her up. Can’t even put the blame on anypony for this.

“I’m sending you to rainbow’s nightmare.”

How did this happen?
 

@Digital Seapony  
Thanks!

@Smudge_Proof  
Long story short, King Galbatorix, the Big Bad of the series, found a way to make it impossible for the heroes to use any verbal spells without his say-so. While it was possible to cast spells non-verbally, it was much more difficult to make them do anything complex, and Galbatorix had literal centuries to cast all kinds of wards around himself which would let him shrug off most magical attacks anyway. The heroes were left with literally no way to attack him, much less kill him.
 
So, in a last ditch attempt, Eragon cast a non-verbal spell that was less of an attack and more of an attempt to communicate, trying to make Galbatorix “understand the wrongness of his actions”. As soon as Eragon’s allies figured out that the spell somehow managed to affect its target, they fed their combined power to the spell, making Galbatorix relive every feeling his actions had ever caused in another living creature.
 
Galbatorix ended up on the floor, swaying from side to side and begging for the pain and grief to stop. Unable to stop the effects of the spell, he proceeded to take his own life moments later (also taking half of the castle with him, as his suicide spell essentially transformed him into a living nuke).
 
Sorry for the wall of text, brevity was never my strong suit. ¯*(ツ)*/¯

CG: I just can’t take so much kindness in one sitting! [bunches up into a ball] Need hatred. [crawls away]

Surely you can do more powerful “reforming spells” than that? The ones that make them be someone that wants it, on every level, rewrite their personality?
 
but seriously, I think death is an appealing alternative to some of these mind control spells, applied nonconsensually

@Wildcard71  
This is all I have really I’m afraid.
 

 
@Digital Seapony  
Can’t say I’m familiar.