Yu-Gi-Oh! Legacy of the Duelist

Surprisingly enough you do not even have to add cards in order to obtain this, what I did "which literally took less than a minute" was from the main menu head into Deck Edit & underneath from where it says #1: Basic Structure Deck (the deck you started with) click on the Empty slot which will take you to another screen showing you all available/unlocked decks & finally click on #1: Basic Structure Deck "or any other deck to duplicate it" give the deck any random name, then rinse & repeat in another empty slot.

probably took you longer to read this than it did to actually unlock the achievement
Thanks guys & enjoy.