KINGDOM HEARTS HD 2.8 Final Chapter Prologue

This one is kind of involved.

First is the explanation of Flick Rush. It is the mini game in KH3D that uses a modified version of the card battling from KHCoM.

You unlock it about halfway through Traverse Town, which is the first world. So it doesn't take long at all to get there.

You need 3 Dream Eaters. When you first get there you may have enough resources to make 3 dream eaters. Both Sora and Riku get a recipe for one dream eater each, so you just have to make a 3rd one at some point.

Once you have 3 you can go into Flick Rush.

I won't explain all of the mechanics because it doesn't matter. The game has tutorials. The important part for this achievement is that if you use the same number card as your opponent you clash and enter into a duel. It is pretty easy to clash. It will happen a bunch of times naturally if you play this mode. Otherwise wait to see what the opponent plays and then play the same number yourself.

Once you enter the duel you will have 3 random symbols. At the bottom of the screen. They can be a cherry, a bell, or a 7. Then there are 3 boxes in the middle of the screen. The first person to fill up all 3 boxes with the same symbol wins the duel and does a ton of damage to the opponent. Whenever you place a symbol in the middle box it replaces the symbol already there and you get another random symbol. As you play you and your opponent are constantly replacing symbols until one of you gets all 3.

For this achievement you have to win the duel by filling the 3 boxes with 7s. It is random because the symbols you get are random and the symbols that start in the middle are random. You can just wait until you get 7s because the opponent is changing out what is in the middle too. Instead you just gotta play it out until you randomly get three 7s or the middle is filled with 7s and you put up the last one.

I actually got this in my first match of the game because I had two 7s and there was one already in the middle so I just threw up my two and got it. Your mileage may very. The only thing you can really do is just keep playing and keep clashing for the duels.