@Background Pony #D986  
We’re here to psychoanalyze colorful pastel ponies, not listen to duckery.

@Background Pony #D986  
Wha…

Hm. Interesting. Although I must say that ‘upsetting childhood memories’ aren’t exactly the zeitgeist anymore. Dangerous zealots must have only one reason for their actions: Religion. Mental stability is irrelevant; Religion must always be the sole reason for becoming a dangerous zealot.  
Especially if that religion is of the anti-democracy, anti-liberty, misogynistic variety. You know, like that one that is always on the front page these days–the religion that one hopeful presidential candidate wants to eliminate from the United States (along with other ‘foreign’ elements).  
Want to write a believable crazy dangerous zealot? make sure you give religion as his primary motivation for his villainy. I bet you he will be 100% accurate and be the most believable realistic villain ever. Not even joking.
 
Oh, in case you’re wondering…I don’t usually wear hats or any other head accessory, nor am I intelligent enough to become euphoric from my own intellect. I also happen to be of average build with 23 BMI and 25% body fat. Although, you may assume correctly that I am male, single and of the age between 20 to 35…

they mus have been torturing that filly with magic as it seems

Batman.

@Cirrus Light  
It doesn’t pass on genetically, the child learns from their parents actions.

It’s a common trope, because it happens in reality.

Most dictators in history did have abusive parents.
 
I think part of it is them inheriting their parents’ genetics, thus the abusive predispositions.
 
But I think being raised in an abusive setting is the larger factor. Gives them a desperate need to be in control of the situation, and they don’t learn how to give and receive love.
 
When Twilight continued to show love towards Starlight even after everything, it must’ve been like drinking water for the first time in days.
 
Of course, Starlight’s parents weren’t abusive, but she said herself she never had any friends after Sunburst left her.