Let's say i have a deck with three Gliscor in it. Could the deck contain one japanese card and two english cards? And kindly post the source where you got the answer as i would also like to read the whole thing . Thanks for your time.
Yes you are allowed. Source, Professorship status.
Remember, if you go to a tournament, you need to have a print of the corresponding page from the card dex, or an English version of the card outside your deck as reference.