Unfortunately, C-z is 0x1a, which is SUB (substitute) in ASCII, while C-y would be EM (end of medium) and C-d is EOT (end of transmission, used in Unix).
(ETX is End of Text) and there’s also EOT, End of Transmission, which is ^D.
Then there’s all of the things we don’t think of as “control” characters but that absolutely did “control” output devices Back in the Day: bell, tab, backspace, form feed, carriage return, newline, etc., as well as Escape. There are really only a moderate number of ASCII characters that are even to this day seldom (if ever) used for their original purpose. C-a through C-f, C-n through C-y, maybe I missed some.
The framing and protocol characters were used some in modem days, but many of them were intended for communication with mainframes that just … took other forms, in the end.