#1 - Reaver voiced the announcement trailer
Simon Callow, who provided the narration for the 2020 announcement trailer- who many mistook for Stephen fry- is actually voicing Reaver
This theory bears no evidence other than both actors happen to be gay :3
#2 - Jack of Blades is OG Hero of Oakvale
This is probably why we don't play as part of the bloodline and why other heroes like us have 'awakened powers'. HoO followed the evil route, and could be a supporting reason for Reaver to have been the next potential Hero of Oakvale instead of the bloodline.
- Reaver, in his haste to defeat Jack of Blades, summoned the Cult of Shadows and wished to become just as powerful to defeat Jack of Blades, but was instead tricked by the Cult of Shadows with yet another fall of Oakvale and cursed with immortality. Incidentally killing everyone he knew and loved, he ends up fleeing In his failure as a hero, and Jack remained further terrorizing Albion throughout our childhood.
This theory bears little evidence other than the way Jack's voice sounds and the way he appears almost in a vision or dream.
#3 - Isabel is NOT the villain of the game and neither is Jack
With the return of Jack of Blades and Wraithmarsh/Bloodstone as major locations, my assumptions are-
1. - Reaver exists in this timeline and did the thing.
2. - Isabel is attempting to avenge her sister's death by using or double-crossing Jack of Blades to get the Sword of Aeons in order to not only defeat Jack, but also Reaver, as the sword is pretty much the only weapon to kill all beings.
'The oldest of all weapons. The Sword of Aeons was bloodforged long before the Old Kingdom. Once unlocked, its power is the power of all Albion.'
In her introductory art, she's clearly hell bent on hunting these cults down and determined in her quest- she truly believes she's the only one who can fix everything.
This theory bears little evidence from the original lore and assumptions.
Final Theory - Isabel COULD be Theresa
"I know why you're here. You want to talk about them."
1. - She indeed has premonitions; she knows what will happen to her and is still determined.
2. - She doesn't, and her sister was Theresa.
This theory is only based on assumptions.
Bonus Theories - Time/Space alteration
With the way tragedies go in this series, I'd assume someone would be willing to undo some things.
1. - The timeline period being in the massive time skip between Fable 1 and 2. Literally the one time Reaver happened to be in his prime.
2. - Theresa's wish from the Spire is canon, and restarted the story. She had a family in this timeline and has 2 daughters, one of them being Isabel who brings about Wraithmarsh.
3. - Scythe, Theresa, and Reaver are off-screen in the background of Albion communicating through supernatural means alongside the Cult of Shadows to try and help the protagonist defeat Jack of Blades. This would be a sort of repentance from Reaver for all the horrible shit he's done idk.
This theory is only based on assumptions.