Square Enix is no stranger to having unique experiences, just look at Kingdom Hearts and its multiple spin-off titles. It has also ventured into the mobile market several times.
Being able to walk in the shoes of the series' Keyblade wielders would be an experience unlike any other. In the world of Kingdom Hearts, you battle the heartless and nobodies on countless Disney worlds. In this AR experience, you would visit each location through portals in the real world, on a journey to stop the heartless from taking over.
With Disney's money and Square's penchant for cutting-edge graphics, it would shine with creative, surreal worlds while showing how massive AR could really be.