Illusion is just the word they try to use to explain what emergence is. I don't think illusion really fits all that well though because illusion implies it's so

Illusion is just the word they try to use to explain what emergence is. I don't think illusion really fits all that well though because illusion implies it's somehow not real and that's not what emergence is about. Emergent things are real (in the sense of Dan Dennett's real patterns) just not fundamental.