Dark October, or Darktober, is the Halloween Event of 2015. This event began on the 9th October 2015, and ended on 1st November 2015. The event included a 'Crack the Code', in which users where given 10 Mysteries to solve. By solving all the mysteries and figuring out the secret code, you were in for a chance to win a special prize.
Crack the Code
On ten different days leading up to Halloween, and including Halloween itself, a new Mystery was unlocked and the users were given the chance to solve it. By solving a mystery you unlocked a code. The code itself can be a Letter, a Sentence, an Image, or an Audio File.
The Big Mystery
Once all 10 mysteries have been solved, you will be able to figure out a super secret code. All users who submitted the correct code before 1st November had the chance to win a Shiny Darkrai.
Three Shiny Darkrai were then raffled off to to those who submitted the correct code. It had been stated by Riako himself that the code is very difficult, and he did not expect more than 10 people to be able to figure it out.