Oooh, which Faroese ballad in particular is that? It sounds awesome!!
It’s called Lokka táttur (Loki’s Tale) and you can read it online here.
In which Loki trolls an actual troll and saves a kid’s life by trickery. But only after the boy’s father goes to Odin and Hoenir for help first, and they’re only able to offer a temporary reprieve. Dad is desperate enough to call on Loki, who not only offers to help but apparently decides that if something is worth solving, it’s worth solving in a permanent way.
By trolling, of course.