Changed System Definitions and now I just get a black screen

in verbose mode

Hey I was trying to get my iMessage to work again Bc it just randomly stopped working. While trying to do that I changed my system definitions.

I changed my system definitions from iMacPro1,1 to iMac18,2. Doing this now won’t let me boot into macOS and just leaves me with a black screen. Any way I can revert this and go back to iMacPro1,1 or any version that could at least let me boot back into the os?

Thank you very much for the help!!