I think I’m finally determined with whooo’s Purple Dusk’s dad. It’s Sunburst! Sorry FlashLight, but you go to the trash, and that’s a reasons why:

- Dusk has a circle in his cutie mark and sloppy nape, same to Sunburst.

- White hoofs fit him a lot

- This explain red color in his palette

- Dusk is thoroughbred unicorn now

- Twilight and Sunburst looks well together (day/night couple)

And yeah, Flurry Heart is crystal earth pony.

Is it fair that she was born Alicorn? Alicorn status must be deserved. But if possible to give Alicorn power, same can take away. It served as a lesson to spoiled Flurry, lesson about that real magic is inside~