Some of my favorite characters are linked to the Spirits from 'Frozen 2'

 

Achim

In one episode of 'Brummkreisel', Achim plays Mother Hulda. Mother Hulda is a fairytale character linked with the Nixies. The spirit of water, the Nøkk, is based on the Nixies.

Lupin III

Although the Earth Giants are explicitly based on the jötunn, Ive heard it theorised that the Earth Giants are influenced by the Formorians. Since the Lupin family's name, in my opinion, is loosely related to the god Lugh, and Lugh is a quarter Formorian, it could inspire some adventure in Ireland.

Lugh was also the grandson of the Earth Goddess Danu, which ties the Lupin family to the Earth symbol further.

I don't know yet which characters I like are connected to the Fire Salamanders or the Sylphs.