This fic should be old, but it had a special place in my heart. Unfortunately I never finished it.
I think it might have been Thorki, but I don't remember well. It was on ff.net (again, I think) It's set after Thor, but before the Avengers (even though they show up, so it's a AU of the Avenger's movie)
Basically Loki ended up on Midgard, and was adopted by a normal family (with 3 kids I think, a girl and 2 boys).
It's a fic about character growth, and Loki becoming a better person.
Just as things are getting stable, the girl from the family finds something strange at her school. If I'm not mistaken, it's a yggdrasil root or branch, and it was magically affecting the kids at her school.
Then the Avengers come and Loki is found. That's what I'd read so far.
Loki bonds with the kids and makes them special magic weapons I think?
If any of you could help me find it, I'd be very very happy.