Old Daikaioshin
is an old Supreme Kaioshin. Which means he was once one of the top ranking Gods that look over the entire Galaxy. He was enspelled many millions of years ago and trapped inside of an old sword until Son Gohan and Son Goku accidently break the sword and release him. He plays a signicant role in defeating the Evil Majin Boo as he has special divine talents that the Supreme Gods of today have forgotten about.
For the cache you must venture deep into the forest of Higashi Son and climb a peak.
Here is the peak as seen from a nearby cache "Jewel of Okinawa"

Old Kai is located on top of the peak on the right. And that peak commands a view truly worthy of a God.

To get to that peak, hike beyond the path that leads to "Jewel of Okinawa" and continue a bit until you find another path that leads up. Follow this path up all the way to the top where it ends at that commanding view above where my two boys are sitting. The hike can be done with little ones of hiking experience but please give yourself 4 - 5 hours to get all the caches in the area and return safely. If only adults and you walk a brisk pace than perhaps two hours is doable.
Once you find the cache you can get a puzzle piece to find a Dragon Ball. GOOD LUCK and safe hiking.
SPOILER.