Some more things that came up while answering comments for FDITH’s Ch14: The Marvelous Madam Marlene that I feel like sharing:
1) I actually headcanon canon!Regulus fairly differently to FDITH!Regulus. Admittedly, part of this is because I’m still developing most and FDITH!Regulus gets to survive and face situations that canon!Regulus didn’t (and there are still sides of FDITH!Regulus we haven’t seen yet), but… yeah… FDITH!Regulus is partly shaped to suit the story I’m trying to write.
2) I was nervous introducing Marlene and I’m honestly still a little nervous about continuing with her, since female characters, especially powerful or talented ones, can get the “Mary Sue” accusations. I’m delighted that people are liking her so far. She’s been developing for quite some time in unposted fics and McKinnon headcanons. If I was going to give Lily Evans a friend, I decided, then she was going to be as interestingly independent as Lily and independently interesting from Lily. A person of her own with strengths and flaws of her own. (Like I’m trying to do with every canon or barely canon character in the story.)
3) I actually headcanon that Divination is a much wider field of magic than just gazing into crystal balls and can actually be intensely practical when approached a certain way by an accomplished/inventive magic-user. So the McKinnons are less… Seers who have visions of the future thrust upon them and more like… people who have to put a lot of work into looking for visions of the future and often don’t find much. There’s a whole lot of past and present world to divine, after all.
4) For example, any sort of tracking spell or scanning spell is part of Divination in my mind. Divination can be and is really useful. It’s just that “pure” Divination gets a lot of flack for being something for drunks and quacks. (I’m trying to decide whether or not to have a headcanon that this is part of some massive, ancient “Cassandra Curse”. I already have a slight headcanon that Divination is a female-dominated field and there’s sexism involved.)
5) One of my all-time favorite personal headcanons (as far as I know, I came up with this on my own) is that Divination is how the Liquid Luck potion works. Liquid Luck temporarily opens a person’s “Inner Eye” to give them a subconscious ability to see the future and decide the path towards the best / most desirable future for them. So a person is having an extended subconscious vision (secondary small headcanon that a lot of Divination involves getting/seeming high) and gets “feelings” that they should just do certain things apparently apropos of nothing.
6) If I make the McKinnons people who practice Divination and can sometimes see the future, then I have to recognize that not a one of them (there’s five of them in total) managed to foresee or prevent their entire family’s murder at the hands of Death Eaters. This horrible irony is going to come up in the fic and I’m looking forward to it.
7) I’m doing my utmost right now to figure out how to put Harry in a reasonable in-story situation for summoning his Patronus. Just for the James & Harry feels. Prongs. (Just thinking about it makes me wanna cry.)