Basically the predestination argument, just replacing God with ‘destiny’. And who determines what is ‘destiny’? Passive observers or those who work to achieve what they believe to be their destinies?
I think Spike is going under the assumption that she becomes a princess because it’s her destiny, rather than it’s her density because she is earns it.
That’d be way too obvious.
Step up your game, bro
You suck Twilight.
Spike > Your Purple Ass.