That seems to be the likely effect of this. Some sort of soccer event that goes on untill the end of the world cup or untill korea gets out. Every time they advance we get items.
If Korea qualifies to the next round of the world cup (currently need to beat or draw Nigiria), all level 16+ characters will win that stone capsule and the speed increase potion.
- Does not specify if it is for all lvl 16 characters in the account or just the account itself
If Korea do progress further, for every round they qualify, they will be issuing prizes.
The notice literally says "HOPE KOREA WINS AND JUST PLAY THE GAME WITH A CHARACTER LEVEL ABOVE 16"