I saw someone else have these, how do you get them? He also had all the gen 4 and 5 legendaries and there is no location for them either.
You can get zebstrika in the electric friend safari.
Unforantely: jelicent can only be obtained through the pokebank, and it's the same with gen4 and gen5 legendaries
here is a list of every Pokemon avaible in the friend safari
here can you get more info about the pokebank
You can only get Zebstrika in Friend Safari or by using PokeTransporter.Source.
And you can only get Jellicent by also using PokeTransporer.(Source)
As for the legendaries,he could have trade them or gotten them from Poketransporter as the are unavailable.Here is a list of all the legendaries in X and Y Serebii.