It's nice to finally have some answers on how Luna bested the seemingly unbeatable Candy Mare! Aside from the first two Something Sweet stories, this is probably the best addition to the series. Though it does make me desperately want to see the more powerful Candy Mare from Cult if the Candy Mare take on Daybreaker. I feel like that might be the only thing that could put her down for good.

Also, I'm usually not one to nit pick on minor errors but you do seem to have mixed up the definitions of peek and peak.

I like when the candy mare loses sometimes
It makes the stories more entertaining