Worlds season pass.
For those who purchase the Worlds 2018 Pass, we expect it to take around 4 games per day (including the First Win of the Day mission and all free missions) throughout Worlds Season 2018 to unlock K/DA Kai'Sa Prestige Edition. Since rarity is a central objective of this skin line, we wanted the additional investment requirement around engagement during this time period. Players can always use event loot purchases as a way to supplement their token earn rates
(so that's on the PBE for the next patch to Unlock the prestige skin, does that mean I've actually already lost the opportunity to get the prestige skin because the tokens have been collectible for awhile ?