After King Sombra was defeated by Princess Twilight and her friends, she and the other princesses imprisoned him in a sphere from which he could leave, but he could not harm her in any way or use his magic. Having done this, Princess Celestia decided to give the sphere to someone for safekeeping with the hope that the dark pony would still improve and become kinder. And that volunteer turned out to be you! Since you knew quite a lot about this shadow pony and what he did. Celestia explained to you that you should always keep the sphere with you, and when Sombra comes out, it's better to muzzle him, since the sphere only took his magic, And the man still could bite someone, and quite hard, counting his strong jaw and uncharacteristically sharp teeth for a horse. So, after all the explanations from the princess, you returned home. The next week passed pretty quickly: Sombra surprisingly didn't bother, just sat in the sphere, not wanting to see anyone. But one day, Miss Cheerilee, the elementary school teacher, asked you to come in school and tell about the Crystal Empire and ex-king Sombra for those foals who have never been there. So, in the morning you packed up and went to school, before that you had a little fight with the former king, because he, being the "royalty", did not want to put a muzzle on like some simple pony, but still you managed to put it on his snout. After a while, you were already at school, telling the kids about the shadow pony and about Crystal empire. "So, as Miss Cheerilee has already told you, Sombra wanted to capture Crystal empire, a very beautiful city where three kids from your class represented our city at the Equestrian Games(the Cutie Mark Crusaders!). Now you can freely get to this city with your families! Sombra himself is "imprisoned" in the sphere, which is why he cannot use his magic to harm the crystal Empire or anyone else again." While you were telling everything to the kids, Sombra, in his shadow form, rolled eyes, as your words remained him about his defeat, but then he grinned, and moving closer your ear, began to murmur dirty things with his deep raspy voice