Hm, a lot of that that Lifemaker wizard said intrigued me. However, I don't think what he said meant the world they are in is fake, as Rakan said.
"Other side", in this sense, means death. That means that every side character, and Rakan, that we have seen has actually died. They aren't necessarily an illusion, nor are they human. What I gather then is that the Code of The Lifemaker is a spell that only works on that particular cross-bred species.
In other words, it doesn't work on those of pure blood, demon or human, but only on these half alien people.
...That's what I've deduced anyway. After all, Rakan was taken to a truly fake place already. If illusions were natural to that world, I don't think it would have surprised him as much as it did a handful of chapters ago.