Story-wise, Alicorns aren’t major players in the Mixed Lore AU story until a LOT of stuff happens, and that’s mainly because of both 1) Alicorns wanting to stay hidden, and 2) the other pony types not even really knowing that Alicorns still exist.
Alicorns are still near immortal beings who have very advanced magic ability, and while there are more than in the canon friendship is Magic, they are still a very small kingdom due to their immortality.
Back when they still interacted with the other ponies, Alicorns were revered as role models of magic use for the other pony types. Even to the present day many Alicorns are still legendary figures in stories. And it’s actually not uncommon for ponies of today to be named after certain Alicorns (which is my clever way of including multiple designs from different gems for the same pony lol…).
While the pony types have a basic knowledge of most of the more well remembered Alicorns, different kingdoms will tell the stories of different Alicorns more often than others (For example the bat ponies talk about Luna more because of her connection to the moon, and the crystal empire talks about Cadence more because of her connection to its origin (more on that in a later post)).
As for some stuff about the Alicorns themselves.
All Alicorns have a combination of All of the Pony Types’ abilities to use PASSIVE magic, just like how in FIM it’s implied that there is a combination of Earth, Pegasus and Unicorn magic. BUT an alicorn’s ACTIVE magic can mean they have a type of magic that seems to come from another pony type more than they have from the other types (see this post for the difference between active and passive magic).
The magic mane (like Celestia and Luna’s and later Twilight’s) is something all Alicorns can have (and actually comes with age, growing to flow on its own and gain extra streaks of color), but the mane completely changing its colors (like Celestia’s going from Pink to Rainbow) is rare due to the fact that there has to be a LOT of magic power there for that to happen.
There have been ponies that weren’t born Alicorns and later became them (a good majority of the known Alicorns actually became Alicorns ie Twilight and Cadence).
This post is getting very long so I’m gonna cut it off here, but I’ll probably end up doing a whole masterpost with backstories for different Alicorns and other elements of the story.
More love for my favourite couple in Equestria. ❤💛💚💙💜
"When I look into your little eyes, I don't know what I see. There's an infinity of possibility in there, a sense of wonder as you begin the greatest journey of exploration, LIFE, and I'm reminded of just how jaded I've become in my own travels."
A parent doesn't leave a child unloved just because their partners children aren't their own biological offspring.
A moment of sweetness between an expectant pony princess, her Bughorse and a whole mess of their little bedbugs. ❤💛💚💙💜