Actually, if the Sword of Aeons and Jack was sent back into the void, wouldn't that mean that they still have a (really petty) chance of returning?
FABLE: THE JOURNEY SPOILERS
The three big antagonists in The Journey are somewhat similar to the three Blades. The Devourer looks exactly like Jack (although since we've never seen the Queen, so we can't say the Temptress looks like her, but it should be "safe" to say so). The Corruptor, according the the lore, feels that the throne belongs to it, since it was a part of William Black, which means that it definitely WASN'T the King of Blades back in the Old Kingdom. However, because of its desire to have the throne, we may call it the King of Blades anyway. Someone once mentioned that the CRAWLER was probably the King of Blades, but after playing through Journey, I now believe that the Crawler is the equivalent to the Knight of Blades, being the weakest of the three lieutenants ( that is also debatable, since it took only Gabriel to finish off the Devourer and Temptress, but it took 6.5 million soldiers to fend off the Crawler).
At the end of Journey, the Corruptor was prevented from entering Albion at the last second, at supposedly the expense of Theresa. The Spire was destroyed again, and possibly most of civilization just like the Old Kingdom's end. Its quite unlikely that the Corruptor will make an appearance right in the the next installment, but there is still Reaver, the Shadow Court (whom we think is connected to the beings of the Void), and that blasted Empress in the Edge (with a possible boss battle with your F3 Hero. Hopefully, they actually use the F3 saves here to change the look of the Hero to how you made him look like, but then if he were to be imprison and corrupted, he would look evil anyway, so maybe there won't be a save reading feature after all, since the Journey effectively undid whatever work you did in F3.)