A Fi and Ghirahim role reversal would be hilarious for a number of reasons, but right now I'm imagining like. You meet Fi for the first time and she goes "There is a 99.999998% chance I will kick your ass," and then you kick her ass. And the next encounter she's knocked her chances of kicking your ass down to 80%. And it just keeps getting lower. Until in the final fight she just goes "Based on previous encounters, I project a near 100% chance you will defeat me. I project a –" [pauses, recalculates] "32% chance my Master will beat you." She attacks you before you can ask why the number is that low.
Demise references it every three sentences or so in a deliberately unbothered way that makes it clear he's DEEPLY annoyed. Then you notice that the number he references keeps getting lower every time he does it, and you realize Fi's talking to him and knocking it down every time he opens his mouth.
