There's no such thing as complete when it comes to stories. Stories are infinite. They are as infinite as worlds.
That's the magic of revisions - every cut is necessary, and every cut hurts, but something new always grows.
Stories have a tendency to seep across the shining membrane walls separating the universes. They whisper and flutter like the feathers of birds, from island to mainland and back again. They fall into dreams like rain.
Each of us is our own story, but none of us is only our own story. The arc of my own personal story is inexplicably and intrinsically linked to the story of my parents and the story of my neighbor and the story of the kid that I met one time. All of us are linked in ways that we don't always see. We are never simply ourselves.
I do open endings on purpose. I expect a lot from my readers. I want them to do much of the work, because I believe that the story is built by the reader, not by the writer. I like having an open ending to a standalone fantasy, because it allows a continuing story to be written in the hearts of the readers.