You are able to create a custom validation message item on sitecore.
First you need to create an item on /sitecore/system/Settings/Forms/Validations.
After you need to create a custom code on Visual studio to render the message with the rule that you want, for example, field is required. After that you need to include your validation item on "
I assume that you are using the Code First Approach. In OOTB JSS, there are no attributes that allows you to specify the validation to use the Fatal Error. However, you can override the import process to have the field to use the fatal error.
Extend your manifest data
First, on the manifest definition, you need to add a new attribute. In my case, I named ...