This part must have been really confusing for Chaz if you take into account, Neithird
Lol, I thought the same, but the truth is that Rune only read his memories; He didn't unlock them, so Chaz still doesn’t remembers Nei3rd. Only Wren, Demi and Rune know their story by this time.
It's interesting that, according to Wren, Rika “inherited Nei's will”.
Rune also inherited Lutz will and, at the end of PSdrama, Nei3rd's inside Rika's mind says:
Nei's Voice wrote:Rudy.... I kept our promise.
So, in the same way Nei3rd isn't in Elsydeon but in Rika's mind (she can't be in two places at the same time), could Lutz be inside Rune too (instead of Elsydeon)?
If this is possible, there would be 2 people we thought they would be in Elsydeon but (hypothetically) may not be: Myau and Lutz