Enforcers appear in the game X-Men Origins: Wolverine. Shotgun wielding guards dressed like Robocop (they're not listed by name in the game, so we're guessing as to what they're called). These guys have shotguns with incredible stopping power, and they use them much more effectively than ghosts. If you rush them, you'll get torn up most of the time. However, unlike their invisible brethren, they don't know how to counter lunge attacks, and this becomes the only way to really effectively combat them with any consistency.