I mention this because they're planeswalkers — so they can literally appear anywhere — and because you might be able to use them in your campaign.
There are nine of them, all told. The leader is a gnome tinkerer from an island off the coast of Faerûn. She is accompanied by a stoic warrior, a psychic goblin with an unfortunate name, two goblin twins (rogues, likely), a
Read about them here.