The two people on the deserted island
We promise we're not going to go through every minor character in the book – we're not going to talk about the witch of Tesk Isle who fails to help Ioethe, or the master of the ship Shadow who asks Ged if he can do magic. Nope, we're not going to say anything about those characters. But we do want to mention the two Kargad people who are on the deserted island.
Now, we don't know much about these people – Ged guesses (correctly, it turns out) that they're probably royal children who were exiled rather than killed when some other royal family took over the Kargad Empire. (Any time you think democracy is messy, just think about competing royal families – so much messier. You probably already know that from HBO's Game of Thrones.)
But their background isn't the most important thing about them. More interesting is that, even though they have nothing and are terrified of Ged, they help him in their own way. Pretty cool. And even though there's not much they can do, Ged and the exiles express some friendship by sharing the little they have – the woman gives Ged an old ring and Ged makes their well reliable and sweet. It's nice to see little friendships even at the end of the world.
(Also, these two totally set up the sequel.)