I owe the character of Khyonessa (Nessa) to my friend.
Originally, I was going to have the book just be about Khioneus (Khi). When I was younger I just wanted the big adventure--Khi the hero, Elkloria the magical land in the crazy magical world, and the Big Bad who needed to be stopped from obtaining their MacGuffin.
My friend came up with Nessa, Khi's twin sister with her own complex background, and now I had so much more that I could do with the story. Now I had emotional plot lines, more nuances to the world, and I could introduce themes like sibling-hood and family. I could also show the world of Elkloria from the perspective of someone who was raised there, and that's really something that I think is awesome.
I owe it to my friend that Nessa exists, and I'm thankful that she gave me Nessa, a truly amazing character and a real gift to my story.