For a variety of reasons, the Seraphim were already rather hazardous. They are not just the newest Pacifista type, but they also feature Lunarian qualities and are projected to get stronger as they age. What's really concerning is their capacity to wield Devil Fruit Powers.
It was revealed in One Piece Chapter 1065, "Six Vegapunks," that the Seraphim could use Devil Fruits. However, it remained unknown whence they obtained their powers or who received whose powers. However, because to the Bartholomew Kuma Seraph, S-Bear, Chapter 1068, "A Genius' Dream," viewers now have a clearer understanding of how the Seraphim's abilities function.
How Do the Devil Fruit Powers of the Seraphim Work?
CP0 utilized S-"power" Bear's to fly from their ship into Egghead's interior. According to Vegapunk Pythagoras, this must have been the Seraph's Paw-Paw Fruit abilities at action. Whether or not this is true, it proves that S-Bear possesses the abilities of the Paw-Paw Fruit.
However, S-Paw-Paw Bear's Fruit abilities cannot be derived from Kuma's fruit. Not only is the former Warlord still alive and well, but he has also utilized his power to transport himself into the same chapter. This must imply that S-Devil Bear's Fruit abilities are a good imitation of the original.
S-Bear being able to teleport like Kuma suggests a few things about the nature of the Seraphim's Devil Fruit abilities. First of all, they are all perfect or at least near-perfect replicas of the original; at the very least, they have enough usability to be implemented into some of the World Government's most expensive cyborgs. Vegapunk must have completed his research on replicating Devil Fruits, which coul have even greater implications for things to come.
The Seraphim using Devil Fruit replicas also means that the original Devil Fruit user doesn't have to be dead for them to have their powers. For example, S-Shark having Señor Pink's Swim-Swim powers doesn't mean that Señor Pink himself is dead. A lot of fans were worried that Franky wouldn't get to canonically have that drink with him, so this comes as good news to them.
Finally, S-Bear having Kuma's Devil Fruit suggests that any other Seraphim who show up will also have the abilities of the Warlord they're modeled after. In the case of Warlords who didn't originally have devil Fruits like Jimbei and Mihawk, an optimal Devil Fruit power will likely be provided to them. This could make the Seraphim greater than or equal to their respective Warlords when combined with the rest of their cybernetic enhancements.
It's a small detail, but S-Bear having Paw-Paw powers says a lot about where the story is headed. It also serves to further elaborate on what the Seraphim are and just how big of a threat they can be. This is to say nothing of how one of them just teleported the primary antagonists of the Egghead Arc through a significant portion of Vegapunk's defenses. Whether they're as powerful as the original Warlords or not, they're clearly not meant to be trifled with.