In the aftermath of a huge explosion in the Everfree Forest, Ponyville soon finds itself as the new home for Lucario, an "Aura Pokemon" from another dimension. While he avoids explaining what has happened to him and where he came from, he repays his new friends' kindness by protecting them from the evil forces that suddenly appears around Equestria.
Meanwhile, a certain princess of the night watches his every move, unable to judge if this new visitor will bring safety or utter destruction upon the land.
(This story primarily takes place between season 2 and season 3. Elements from season 3 may occur, but won't have a significant impact on the plot.)