Im not a moderator, but id like to give my opinion on this

There's a lot of other games where a new bug its discovered and it breaks the game, and the response to that is to make another category (0 Stars Mario 64 for example). I dont think this will be needed for Eric Carter Prototype, since its a very easy bug to do

Since as you say

In my opinion the combination "Eric Carter with Prototype" should not be valid or at most a category would be created just for "Eric Carter with Prototype", But logically this could make things more confusing and I don't even know how we would do these new ones categories

It may be very confusing or difficult to make that new category, i think the easier solution to this is just make the records with Eric Carter Prototype VALID IN SOME CATEGORIES

You'll need to add a straight to the point guide on how to use Eric Carter Prototype, for newcomers to know, also you'll need to update the rules on the categories where it will be banned