Modding

Most likely, in NHF, something similar was done with Laslo; usually, a standard Knight is taken, and the model of a flagless Knight is applied as an effect. In this case, only the battle model is changed, so there's no need to worry about the move animation and model highlighting on the map.

Yes, Laslo (and not only him) has a special unique model, but his body is essentially an effect placed on top of a regular transparent model. However, in NHF, this is also present. But I did it simpler by attaching a renegade helmet to a regular body, and there's also a shield that belongs to some hero... I don't remember which one... and I also attached a renegade sword to someone!