AC97 
"[@cheezedoodle":](/pony/season-9-discussion-thread-warning-spoilers/post/4491101#post_4491101
)
Regarding Horse Play, yes, the part with draining magic was addressed, but that part was lifted from The Journal of the Two Sisters, which said that Star Swirl had aged himself raising the sun, hence why his hair is white.
The latter part has never been addressed in the show, and something that also hasn't been addressed is whether Celestia and Luna were born alicorns or not (in the book, they were, and the only way to reconcile this based off of what Celestia and Luna said in The Crystalling is them going by Exact Words for no discernible reason [_not_ chiming in when Rarity said that she thought princess wings had to be earned by saying "actually, we were born this way too"]; something that got thrown out by the show is Star Swirl bringing them to the Tree of Harmony).
I think it's not really up for debate that in canon, Celestia has probably_*always_* had a horn, either way, otherwise, she probably wouldn't have been Star Swirl's student, if she wasn't a unicorn to start out. (Could probably argue her starting as other races maybe, but who knows, we're probably not getting a flashback episode explaining this, nor do I think they really need one)
Another thing that's been thrown out from that book is that Commander Hurricane was the only stallion amongst the six Founders of Equestria... which Clover the Clever is actually male, going by Forgotten Friendship.
Regarding Horse Play, yes, the part with draining magic was addressed, but that part was lifted from The Journal of the Two Sisters, which said that Star Swirl had aged himself raising the sun, hence why his hair is white.
The latter part has never been addressed in the show, and something that also hasn't been addressed is whether Celestia and Luna were born alicorns or not (in the book, they were, and the only way to reconcile this based off of what Celestia and Luna said in The Crystalling is them going by Exact Words for no discernible reason [_not_ chiming in when Rarity said that she thought princess wings had to be earned by saying "actually, we were born this way too"]; something that got thrown out by the show is Star Swirl bringing them to the Tree of Harmony).
I think it's not really up for debate that in canon, Celestia has probably
Another thing that's been thrown out from that book is that Commander Hurricane was the only stallion amongst the six Founders of Equestria... which Clover the Clever is actually male, going by Forgotten Friendship.