As someone who has already done promos with voices and internal monologues, I don't think you can ever go too far. xD The way I like to envisage it is that all my promos are video packages with the voices done as a voice over so that the audience knows what's going on, or I create these kind of entities (done with special effects) so that the voices almost become real. I understand that's still not easy for the opponent to respond to because, in character, they wouldn't be hearing these voices, which is why I always have The Riddler talk about my opponents and use the voices in his head to basically concentrate on him, not his opponent(s).