@Starlight Storm  
let us remember one thing though. she did not start giong in behind starswhirl’s back until after she was forced to banished luna. so she was not diong this before, she was visiting whenever a trip was planned and nothing more.
 
losing luna by her own hand changed that. having your own sister turn demonic and try to kill you is bad enough. being forced to imprison her for her own good and the good of others is even worse……. the thoughts of whether or not you could have done something to stop it is when it all becomes unbearable.
 
basically at first it was mostly the alternate sombra. after losing luna she had both her lover and an alternate of her sister who had not fallen into madness, whom she did not have to hurt anymore.
 
what i like about this arc is that it sets up the perfect storm for her behavior. it all occurs during the time she was most emotionally unsound, when her duty to her kingdom forced her to hurt her own sister, when she was all but left alone in her own world.  
if she had started the whole go to the world behind starswhirls back thing before losign luna then i would agree. but it all started after. at this point she simply did not care. if it could bring her solace, it was worth any risk. and to be honest it is not hard to blame her for that. she did wrong, she should never had done her constant trips, yet she had the choice of either listening to those warnings and being haunted by what she did, and running away from her responsiblities and sins to a world where her sister was unharmed and the pony she loved ruled.

@Background Pony #E2D5  
@RIG
 
I must admit this actually makes her desires to remain in the Mirror World make sense. In fact, this justfies MOST OF her decisions… Although not all of them. Admit it: Travelling Once again after Starswirl forbid her, told her why and made her promise so, causing the whole paradox problem, was WAY too idiotic and immature of her.  
…Well, at least this gives a little more background on her.

@RIG  
though to be fair neither lunas were outright evil during this time either. prime luna was darker but seemingly did not become nightmare moon til decades later.  
so it ultimately leaves the story of prime sombra a mystery. was he outright evil from the start? or did something terrible occur?

@Background Pony #131A  
also if you follow it they first met alternate sombra when luna was still around in their world, if she was slowly heading down the path to nightmare moon.  
decades later she banished luna, and kept on visiting the alternate world to find comfort behind starswhirl’s back.

@Background Pony #131A  
after meeting Godd Sombra for the first time, Starswirl theorizes that there may be a sombra in their universe too and that he may be evil  
 
with this, is easy to assume they meet good sombra before evil sombra and the nightmare moon incident.

@RIG  
………… i just realized that is what this was all about. celestia was trying to escape her duties and grief. she craved solace and craved to be in the world where she never banished luna and she had someone she loved.
 
i do not see why so many people are bashing celestia though. this, this was her long ago in the past, this was her fresh from the guilt and grief of not only failing to protect her sister, but being forced to imprison her by her own hoof. as you said, she sought escape, and she began to crave it.

@Background Pony #131A  
simple. she met alternate sombra before the crystal empire incident.  
and this makes it even more clear they used theri own powers against him. could simply be there was too much disparity between her and luna to use them for starters. and him still being alive after the fight may be her not wanting to off even her lover’s corrupt alternate.

@Background Pony #131A  
Pretty much, yeah.

Wait, in S3 opener, Celestia told she and Luna banished Sombra, so it happened before Nightmare Moon incident, but according to this comic, Celestia had no idea who Sombra was even after NMM. Does this mean IDW(comic) and DHX(TV-series) are in their own universes or something?

Mega super downer. ForeveraloneCelestia confirmed?

@albert19  
“Temporary solace.”  
Temporary is the key word.

@albert19  
Who knows?
 
Nobody.

So who ruled Equestria while Celestia was gone?

O.O  
I really like her mane…

Where do you buy these? The only one I saw was at a con I went to.

escapisms confirmed.