Most Galdrar would be classified as "blue magic" in your world, then. I can't think of any that work offensively.

[There's some hesitation before Sephiran speaks again, as though he's thinking about something.] I used to be able to sing Galdr, but then... some circumstances passed, and now I cannot use it. [He's blowing his cover a bit here, but does he really need to maintain it in this world, anyway?]