Is it possible to get a local event pokemon over trade (not self redeemed) and that it doesn't show the wondercard in your card album when it's traded to your DS (or is that a normal thing actually?)?
Yes, local indeed. More info on it:
http://bulbapedia.bulbagarden.net/wiki/List_of_local_event_Pokémon_distributions_in_Generation_VI#2016_Korean_World_Championship_Series_Mewtwo
An add to the missing wondercards list is the Korean Championships shiny Mewtwo (ID: 05056 - OT: WCSK16), which ran from 5th may till 8th may. Hopefully someone is able to obtain this mighty Pokemon.