That's a cool pitch.Ah, from spoilers:end of spoilers
when Loki was in Sif's body.
hmmm... depends on how raised I guess? Genetically should be the same as several of the others.
One that occurred to me: Who in Thor's stories has had reason to want to seduce him that's not Hela or Amora? The Svartalfr queen: Alflyse
Alflyse once tried to marry Thor, but that went wrong because the man she thought was Thor was actually Hercules. It's kinda said that Thor had a much different opinion of her than Herc, and thus no interest in marrying her, but... Alflyse had interest in making Thor her consort. The bit about how Alflyse only got mad at Herc for lying to her was interesting, but that's because she was genuinely trying to forge an "alliance" with Thor.
I still question if Hercules's interactions with Alflyse may have given her a child. Yeah Greek demi-god mixed with a Dark Elf... that could be fun. But in an alt-timeline... maybe Alflyse could find a way to get Thor to give her a child?
Hmmm the only example we've seen in canon is a guy who was born with an innate gift for shapeshifting, but I don't think that'd be typical... since neither parent does that. But it is common for Dark Elves to have illusion magic. Hmm... a child of Thor with similar strength, but also Svartalfr magic to create illusions in combat? hmm... that's got potential. Also the Svartalfr weakness to cold iron seem weakened with mixed blood lines.