There may be some spoilers in this thread so be warned if you have not finished fable TLC and Fable 2 with all the expansions. If you do not want to read all of this post for some odd reason, the gist of my post starts after the dotted line.
In Fable TLC we fought Jack of Blades and defeated him. Twice. His cunning skill and evil mind brought us to our knees as we played through TLC. This knight had a mind of no other and a sprit that haunted Albion for millennia.
After defeating him we chose weather to toss his soul into the lava or have Jack reincarnated himself in ourselves as we place the mask upon our face and become Jack himself.
After time, around the time that Fable 2 took place, The story of the hero that slew Jack was not kept correctly and we do not know whether he was thrown away or kept living as the hero placed it upon his face.
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Nonetheless, The King of Albion was granted a wish in his younger years as he fought to defeat Lord Lucien and found the three heroes and was granted a single wish... More money than he could imagine, the resurrection of those lost in the re-making of the spire, or to bring back his sister, dog, and family.
If you beat the game and chose the card to bring back your sister you will get a note from her;
"Dear Sparrow,
I woke up today in a peculiar place. It's like a big forest with lots and lots of trees that go of forever. I was scared at first because I couldn't find you, but there's someone here that says he knows us, says he knows our family. He told me his name but I keep forgetting it. Weird. I think he's a King or something. He's very thin and wears a hood and looks scary, but he's nice and I feel same with him here. I hope you're okay Little Sparrow. I somehow know that it's all going to be all right, and we'll be together again one day. He promised me.
Love
Rose"
Jack of Blades was thin and wore a hood. It doesn't take a rocket scientist to figure that one out. In Fable TLC he knew all about your family and used it to bring his sword back to existence. If he wants to know something he will end up knowing it as we have learned. Theresa went to a far away place when you chose not to kill her in TLC. She is an old woman in Fable 2 and at the end of "Back to the Future" the salesman that gives you his oddities finally give you a spire statue that takes you to see Theresa and the salesman later tells you that you should now know the source of the oddities that he has been giving you.
His source is Theresa! She gave Murgo the magical Music Box, which started all of the quest lines for Fable 2! Everything in Fable 2 was planned. According to Fable TLC who was the greatest planner in the game who set you up to get what he wanted? Jack of Blades.
My opinion is that Jack WILL reappear in Fable 3. As the note stated; "He looks like a king or something", Jack of Blades is probably trying to steal your rule over Albion in Fable 3.
Tell me what you think!