I'm not 100% sure, but from what I understood, it means that the roles of almlst everyone switched. Meaning, Kiriki (man) is not the game Saintess, as said by Eve and Gozu, because he just replaced someone else. Same for Gozu, but we don't know who he replaced. But by seeing that panel of the game Saintess' and Eve' faces superimposed, it is safe to assume that Eve too replaced someone else: he was supposed to be the Saintess, but ended up being the Demon King.
My own personal theory is that the character that Gozu replaced is the game hero! But again, take my theory with a grain of salt.
Lowkey... i think gozu was/is?? The hero
I compared the back gozu's head with the back of thr hero's head and HMMM MIGHTY SUS
Also rereading it, the item shop guy knew about kiriki?! But his idea of kiriki was a holy WOMAN?? At that point, kiriki was both a man and the saintess' name has not been announced

I should've known when Gozu said that the saintess looked similar to Eve... Looks like the answer was right in front of us