"Let's see...I know he's a Caster possessed by someone else, and I can't even begin to tell you how many ways that should be impossible given my own understanding of how the system works."

In terms of how Chaldea's system functioned, Waver was at best misinformed and at worst hilariously wrong.

"On top of that, given something you mentioned earlier, he and I are likely to have drastically different experiences with Fuyuki. But that's effectively all I know."