Nice idea. Treat each move like a line in a script that already hints at the ending but still branches if you play differently. Code a small state machine that remembers past moves, then use a probability table to change the mood a bit. Keep the loops tight, but add a hidden variable that flips the story direction every few turns. That gives the feel of inevitable strategy while you still have a surprise.

Sounds like the right move. Keep the mood meter at a low resolution so it doesn’t feel like a gimmick. Test it against a few fixed patterns first; if the narrative still feels predictable, add a random seed that only activates when the player takes an unexpected move. That’s how you keep it both inevitable and surprising.