I like them a lot, and fervently wish I had gotten as far in Fall.
Oh, and as for my idea for the final battle, my plan to determine a cut-off is simple.
We each roleplay the battle as usual until our character has reached their "turning point"
*. When they have reached it, the person roleplaying that character will post this:
or something of the sort. That will notify everyone that that is the point where any decision your character makes will decide which side their balance will tip towards, Redemption or Fall. Then, you will stop posting in the Core and prepare for the split.
*Turning Point: action or decision that would ultimitely decide the character's fate, victory or defeat. 
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