[Tiavals]

I'd really like it if Jotunheim(of all ages perhaps?) could summon Rimtursar. Huge, size 6 giants with monstrous magic abilities. That'd be awesome.

Also, for Vanheim the ability to summon Aesir.

I do so like the god-like beings from the beginnings of time. More high level summon spells that can evoke them. Thematic spells for every nation. Some nations don't always have even a single one, I think?