"Long, long ago, the crystals collaborated their energy to seal away creatures of massive power into another realm. This realm was an eternal prison for them. Punishment for their crimes against ponies, and to save us from their terrible power. They were to live forever without color in the darkness of their own rage and sorrow. This prison is called the Shadow Realm." "Uncle Eight Star, that sounds like a load of-" "Chishi Cherrystripe! Manners, please! This is history, not fiction." "Pfft... yeah right! If such a place with these scaaaaary monsters exists, then show me!" "I have a better plan... let me gather a couple of babysitters to show you. Uncle Eight Star has work to do."
"Yes! Apprentice Quill, I need you to experience the Shadow Realm first hand. Take some of the protection gems in the study and grab some free agents before taking Cherrystripe with you to explore. I expect the experience to be enlightening."