Long ago, there was a herd of ponies named "Shadow" ponies. They worked for Luna in the background, never given credit in the public. Most of the herd were comprised of earth ponies. Rarely there were unicorns within the bloodline, but there were no pegasi. Pegasi and ponies of their herd never crossed paths at night.
The Shadow ponies were only seen when it was dark outside. That's when their dark coats blended into the shadows of the night. It allowed them to carry out their quests silently and unseen by others.
It was shortly after Luna's banishment that they were exposed. The other ponies feared they might rise up against them in rebellion. The fact that they arose during the night only added to their fears.
"Order! Order! We are here to discuss what is to be done about these "Shadow" ponies" said the head of the council. The crowd began speaking their fears and suggestions on what to do.
"We should strike before they do! It's that simple."
"Yes, before they destroy our villages. They will surely rise against us. Celestia has taken away their deity. Everyday we prolong taking action is another day they have to plot."
"Not to mention that one pony. He has took away souls from ponies. They probably hired him."
"They apparently sleep during the day. It would be a easy task to get rid of them then."
Celestia came through the doors of the town hall. The council murmured amongst one another as she walked down the aisle. She began to speak to them.
"We should not hold all responsible for the sins of one pony. I believe that they will not cause any trouble. And no, there is no connection between that rogue pony and the Shadow guards. He was captured and dealt with accordingly."
The head of the council stood up.
"If we cannot kill them, then may I suggest we simply exile them? I know they could not survive on the moon like your sister, but how about just out of Equestria? Just far enough to make sure they cannot affect us here."
Whispers filled the room from other ponies in the audience.
"That sounds better than letting them stay here."
"Heh, I'll make sure they don't do anything if she lets them stay here."
"Right. I won't be able to sleep at night if I know they roam the streets. Who would be awake to stop them from doing anything? Something would have to be done. They have no other purpose now."
Celestia protested, but the cries from the other ponies for them to exile the Shadow ponies was powerful. She saw that if she did not do something, the others may take action into their own hoofs. Having just banished her sister, she did not want any bloodshed. With a heavy heart, she signed a declaration of exile for those who served in her sister's royal guard. And with that, any and all ponies that served Luna was removed from Equestria.