Sprites stand about one to two feet tall with rainbow tinted gossamer wings
I've concepted them as less "extreme", yes. They're a more subdued - tricksters still, but less for the novelty of the thing and more for the change it evokes in the world that others must contend with. If you wikipedia 'pixie' you might see where this idea came from.
Classically, pixies are allergic to silver. We don't have silver, but iron would do. Instead of chosing iron, which seems like it would be a common weapon type at lower levels, I chose other metals that are likely to be available in midrange mobs, as well as the end game. Presumably the race itself would be enjoyable and well made enough not to require direct correlation between vulnerabilities and resistances.
I agree on the name. Pixie or brownie would easily be better.
