I have problems understanding how いざ...や works in the following sentence.
I'm quite sure that it means something like "Even if it was the document of the department head, Nitsuta thought, it would never get approved. But when a written complaint actually arrived, his boss fully acknowledged the claims and the dispute ended with a complete loss for Nitsuta."
but when I tried to determine the exact meaning of いざ...や I couldn't find a fully satisfying explanation. For いざ I am pretty sure it fits the explanation ① of weblio (https://www.weblio.jp/content/%E3%81%84%E3%81%96) indicating that something reached a certain stage/a development came to a critical point but I can't really make out why や is added afterwards... Is や only added for emphasis similar to the explanation in this thread? 桜桜ーいざや and ゆかん meanings But if so, how does it work? Could I use いざ...や every time I wanna emphasize that it "actually came to ..."?