There are images of Arbus & Solaseed, they may be used for story first but they may be playable characters at some point (I guess that because they have several voice lines and types of images that are uncommon for NPC)
As you can see there is the name « kon » and not « rezero » in the file name, it’s because they renamed their rezero data to kon so it’s harder for the dataminers to know what it is
