Board Thread:Theories and Rumors/@comment-39018852-20190721011747/@comment-1838757-20190722210840

As you've already said, it seems like Pyro Vipers are just an army of zombies brought back to "life" by Aspheera's magic and empowered with fire stolen from Kai and never really had any connections to this element in the past.

To be honest, the Serpentine from the flashbacks seem to look more like Hypnobrai's predecessors than a new and distinct tribe to me (also Char kinda looks like a Constrictai). That may very well be the case, that they aren't really anything more than just some Ancient Serpentine.