A mysterious figure, living in shadows, is attacking seemingly random crime leaders and leaving little to no trace. The Mane Six investigate, but they find a secret more startling than what they had ever imagined.
Sunset Shimmer's Hearth's Warming Eve celebration is cut short when she spots a suspicious figure lurking outside. After a festive costume makeover, she sets out as the Mysterious Mare-Do-Well to investigate.
In another dimension, Sunset Shimmer and the Rainbooms are now sending fear and panic to the students of CHS. But maybe three sisters may put an end to that...
The Rainbooms are back in New York to help their friends the Turtles take on old threats and new threats, but this time with the help of old rivals and an old friend.
The turtles and their human friends have been to New York, Space, and Camp, now they enter a whole new world populated by pony folk and many other types of creatures.