To be honest when they said you get a mystery champ I brushed it off because I had all of the champions and just recently learned that you couldve gotten a mystery skin instead.
Is it too late to get it now since apparently you cant register for it but the rewards havent all been distributed....
According to a Riot comment from this thread http://boards.na.leagueoflegends.com/en/c/miscellaneous/sEwlovv8-facebook-free-mystery-champion
You needed to have your League account linked to your Facebook account from 11:59PM PDT on 6/28 through 11:59PM PDT on 6/29, otherwise you will not receive the mystery champion (skin if you own all champions).
that sucks :(
thx
Pretty sure it's too late ;c
