Posting a bunch of my fire emblem head canons in hopes that this post overtakes the Edelgard post I made two years ago
Grima was not made evil like Forneus's notes would tell, Grima was instead made more akin to a curious, pure hearted child, and began taking on and reflecting back at Forneus his own twisted thoughts after Forneus gave it his blood in hopes that Forneus would comfort it and help it remove those thoughts. Forneus instead used that as a way to make Grima into a scape goat for his wickedness.
Alm and Celica are accidentally responsible for solidifying Grimas hatred of humanity because of them attacking it without warning and not even bothering to try and communicate.
Grimas more innocent childhood self still exists as a sort of angel on Grimas shoulder, though only the Halloween Grimas in Askr notice its voice.
Manaketes, like real life lizards, enjoy sunbathing on a warm rock. This also includes half dragons like Corrin but they're more embarrassed about it.
Whether or not a Fell dragon is evil can be figured out by just asking if they like sweet foods. They don't? Then no, they do? Then yes.
Shareena has incredible game. It will never see proper use, because Shareena does not believe in sex, only friendship.
Reginn and Kiran dated for a bit, before deciding they were better off as friends and breaking it off. They still joke about it.
Dagr and Baldr pass Alfonse around like a blunt.
Smash bros is canon and did happen to some of the FEH versions of those fire emblem characters. This has led to Kiran unironically hearing from Marths mouth "I would like to see sir Sonic once again, if only to test his claim of experience with a blade."
Kiran and Heoir have a father/mother daughter relationship. Gullveig is unsure how to tell them that's actually the case.
Gullveig doms Kiran so that for once she isn't the one getting royally fucked.
Kiran is well aware that Peony and Shareena switched lives at some point in their youth. They don't bring it up out of fear of what Triandra will do to them if they mention it.
Kiran once told an enemy combatant that if they didn't leave the battlefield they'd shove Breidalbak where the sun doesn't shine and fire.
Kiran is immensely sad at Rune having turned out to be an enemy. Alfonse is shockingly unbothered by it and it worries them.
If you throw a stick in front of them, Kurt will chase it.
Arval keeps a score of how many times and how long it took for Shez to just absolutely eat shit.
