After defeating King Sombra and helping to save the Crystal Empire, the Mane 6 should've been completely done with him, right? Wrong! King Sombra suddenly returns! Like in a physical body and everything. Does he want revenge for his plans to return to power being ruined? Does he want to try and enslave Ponyville? Only the dark unicorn King can answer these questions.
*This takes place somewhere between seasons 5 and 6, so if there are any inconsistencies occur, you know why*
Don't worry, I will return to this story once I get over my writers block