you prove an excellent point although she is the only pony who had the intentions of killing twilight rather then feeding off of her love, or driving her into chaos for the fun of it. Or in the case of Sombra just making them his slaves.
its good if you can find it online its worth downloading it. the story is a little stereotypical in some parts but overall it has a well written line of story.
i think they should keep him in, but he probably wont have a relationship with twilight. maybe he will become the next leader of the royal guard who knows.