it's DB's first Hidden Event!
To get the secret rewards, you must spend all your stamina running dungeons to find the Special Prize Dungeons.
They're different fro everyone, so no telling our guildmates which ones!
Then spend all your raid tickets- the more raids you win, the higher the multiple is attached to the Special Rewards in the Secret Dungeons!
And don't forget to spend all your gems on buying the great runes unlocked in the store once you complete a certain number of secret dungeons!
Remember, if you don't find the Secret Reward Dungeons, keep trying!