Noxiel, Angel of the night, followed by the Night itself, might have made a mistake. While he bore the title of Tyarel, Angel of Knowledge, he discovered that he was an artificial soul, created by his former lives, long time ago. Actually, you might call this immortality through rebirth.
His research had influenced the whole multiverse, being against the first god command to angel, ''do not create life''. The crossing of this rule had been made on the human world, called purgatory, and in Equus.
It's up to the newly-created soul Noxiel to fix his former life's mistake. Will he handle it and go back home, or will he fail, and remain trapped in Equestria forever?

And, the most difficult question even he can't answer: would he really be mad, sad or angry, if he was trapped in Equestria?