I have an idea for a series revamp: Call it "pieces of Eden" or something related to that and just have different eras each game. E.g. Assassins, Pirates, samurais and more. The main story that they all follow could be a group of treasure hunters in the near future who have discovered the dark secret of humanity's past that we used to be enslaved by those who came before, who enslaved us by the pieces of Eden. There could be choices throughout the games such as whether to destroy the pieces in the future part of the story or use it to control your enemies (keeping the pieces, however, will result in bad reputation with NPCs).