The Younger Kain
An early Gamespot preview of Soul Reaver 2 described an interesting potential consequence of the time travel in the story:
Furthermore, you'll have two Kains to contend with, one the uberdemon from the second game, and the other who is mere footsteps away from beginning his reign of terror.
This aspect of the game was never mentioned anywhere else. If it was a plot element at one time, it does not appear to have survived very far into the development process of the game. There is no known concept art depicting the young Kain in Soul Reaver 2. It is possible that Gamespot's statement was based on their misinterpretation of information passed to them by Crystal Dynamics. Raziel does visit an area where Kain "is mere footsteps away from beginning his reign of terror", but the two never meet.