The gorosei will posess entirely new type of devil fruits we haven't been introduced to yet
Luffy's Fruit and Law's Fruit are just on a different level to other Paramecia Fruits.
I found it odd that Luffy's Fruit was originally classified in the series as a Paramecia, because that's how it seemed to actually function up until the Time Skip. No one guessed it was a Zoan, because it didn't function like one up until Gear 4 (which I guess can be looked at as some kind of "Pre-Awakening"
I think Luffy and Law's Fruit should have their own category, and that the Gorosie also have Fruits on this level.
Conceptual Devil Fruits. Fruits that alter the concepts of reality. We see this with Law dissecting reality, and Luffy manipulating it. Might be good to look into Alchemic representations of Saturn and the other planets, to see if those could connect to what Fruits the Gorosei could have.