When Grey Knights use a rule that is meant to harm demons, does a Demon Prince count?Is a Demon Prince a demon? Really? That's the question? Believe it or not, it's a hotly debated dilemma and with good reason. There are units in 40k that have a "Demon" special rule such as the Eldar Avatar and pretty much everything in Codex: Chaos Demons. However some units that you would think would have some sort of solid "Demon" rule (like Demon Princes or Summoned Greater/Lesser Demons) do not. Odd, right? Well don't forget that the Demonhunters codex is old. Back then you would follow what the codex defined as Demons which is not incredibly helpful for us.
However, there is a nice little trinket to chew on in support of the logical "Demon Prince is Demon" theory. Page 8 in Codex Demonhunters underneath the "Demonic Infestation" entry states:
Demon Packs, Nurglings and Demon Beast Packs (but not Greater Demons, Demon Princes or any type of Demon) gained the Sustained Attack scenario....I truncated the quote as it is inapplicable here anyway. What this little section does is list which demons gain a special rule when fighting against Demonhunters and which do not. Demon Princes are listed under the do not. Therefore Demon Princes are Demons.
Personally I think this whole argument is stupid. If you want to argue that Demon Princes (and Summoned Lesser/Greater Demons at that) are not Demons do to a minor oversight on adding "Demon" in their entry then fine. Expect a team of pirate-zombie-ninjas to be dispatched to your house and slap you across the face with spiky mallet.
Terran Forge Final Opinion: Don't be a power-gamer. A Demon Prince is a demon. Duh.
Ignore the overly aggressive tone, it's just a very annoying argument to hear. 40k has its messed up rules and inconsistencies, but this no where near as bad as some other ones. As always, feel free to email us with rules questions! And please leave comments with your opinions!