Sequel to Another Q joke.

A thosand year ago, Nightmare Moon created a doomsday weapon. It had the power to destroy a sun, but the Misstress of the night never meant to use it. One of her subjects decided to do activate it himself. Nightmare had no choice but to banish him and the device to the Void.
Somehow, the device came back and resurfaced on another universe, it is now up to the mane 6 to finally put an end to this.