In the level 50 quest, your Darkside tells you that they will be waiting should you ever call for them to “take the reins”.

Originally Posted by
Your Darkside
…If this is how it must be, then so be it. But know that when you tire of this charade, I shall be here…waiting to take the reins… You need only ask…
In the level 70 quest, when you confront Myste in The Peaks, you’re given the choice to say “I tire of this charade”. Given this, it ties in more directly with the being that appears as “Fray” in the level 70 quest being your self that you fought in the level 50 quest.
We never knew the real Fray. The being that was with us all through the 30-50 quest chain was ourself.
Personally, the only reason I think they didn’t make Living Shadow a copy of our characters is “technical limitations”. Not the best excuse, but I’d rather see myself fighting alongside the Me I interacted with from level 30 to 50 and fought in the level 50 quest. That feels more touching, in my opinion.