Mystic Quest still gets almost nothing but hate for everything except the music. It’s entirely undeserved, and maybe the next few years of promoting accessible gaming will get it a fresh look.
As far as I’m concerned, nobody in a timeline knows how time travel works, or how paradoxes are resolved, until SOMEONE GOES BACK IN TIME. For all we know, the rules about it aren’t even set yet until that happens. (And if Star Trek is any indication, even then they’re still in flux. There are at least four different models working in that canon.) And just because a model seems like it’s impossible (like Back to the Future), doesn’t actually mean it is impossible; it probably just means that it’s deity-aided.
That said… obviously, unicorns have done time travel before and they should know what the rules are. They may not remember. Or they may have been too self-absorbed to notice. But their rules are likely set.
Well, by unicorn court ruling, Phoebe is in fact a unicorn, so at least that’s not the embarrassing part.