[How could he lose his memories?? His injuries aren't even related to his brain!]
Zev refused to believe Ainsley's words.
If he believed her, it means admitting the fact that the Godfather wouldn't remember him or Ainsley anymore.
Especially Zev. He didn't have any connection to the Godfather if not for his identity as the Godfather's former system.
Once the Godfather forgot Zev's existence, there's nothing that could prove their relationships, unlike Ainsley, who still had her shaman link connected to the Godfather.
Zev felt like the future would be bleak. He is a system's spirit, but he has emotions akin to that of humans. He had good feelings toward the Godfather.
How could he accept that the Godfather forgot him and even acted that way??
Zev started to bawl and cry while also thinking of a way to restore the Godfather's memory.