This system provides power (a small boost) for every star upgrade you from your ninjas. Let's say you have 10 3* and 4*4, which you have 46 stars in total and you get the power boost of having 46 stars.

The coins we have in the shops will be all combined (except for summon and space time) and split into two coins (sun and moon). Some ninjas will be able to be purchased via the coins. Some old ninjas you can get from the shops we have and some new ones such as gnw hinata, fu, danzo, etc. Keep in mind the newer the treasure, the more expensive it would cost per frag. At the moment, super rares in treasures cannot be pieced in this system and I highly doubt they would ever appear since it defeats the purpose of being a "super rare".