This is a port of the eriner zsh theme to the Ion shell.
It depends on some basic unix utilities, and it is unknown if it works on non-Linux systems.
Currently, it has a decent amount of the functionality of the original theme; more functionality will be added as the capabilities of the Ion shell increase.
Simply download the script, source it in your initrc for Ion, and set the contents of your PROMPT function to prompt_eriner_main.
If you'd like to customize it, I highly recommend the Ion syntax highlighting plugin for vim developed by vmchale.