//I've always assumed that Alicorns aren't inherently immortal, and the reason Celestia and Luna seem ageless is because their lifeforce is connected to the celestial bodies they represent, so they can't die of old age but can die if the sun and moon were destroyed. I also believe it is possible for them to be killed by conventional means. Celestia has shown that she can feel physical pain, which is something an immortal being would have no use for.
Oh I’m fully aware they’re not INVULNERABLE, but they’re definitely immortal in the sense they can’t die by aging. If that’s because of their ties to the sun and moon exactly, I don’t know. I suppose it’s possible.
If that is the case, how that connection formed in the first place is another matter altogether. Ponies who raised the sun and moon before celestia and luna were unlikely to be immortal, after all. was it because the magic they created to become alicorns was linked to the sun and moon?
it’s an interesting theory~
i like to think that the longer they built this magical connection with the sun and moon, the more it tied them to equestria. were celestial bodies themselves involved? did it have something to do with the tree of harmony? Celestia and Luna’s cutie marks were on it from the moment it came into existence, after all. Did its magic help in some way to retain harmony and keep the cycle of day and night moving?
It’s all conjecture at this point, but makes good headcanon fodder lmao