this is an extremely vague description and i dont really see what the problem is, to answer your question, i think what you want to do is make a pawn class, have all events and variables that both creatures and characters will ahve in there. then make a child class for a character, then one for a creature, with more specific varialbes and events in them. Then continue making child blueprints off of those two. interfaces are a little different in unreal than standard coding, their used more for blueprint communication than anything else, but if there is more functionality that for some reason you cant put in the parent class and numerous blueprints will use them, you can use an interface for that