It is a signature move ... well. No. People thought it was a signature move for them for a while. But now they have realized that there is a legendary that can also perform it.

[ which is still very funnily limited distribution, but disqualifies it from counting as signature! ]

They are different but ghost and dark usually have a lot of overlap... [ super effective against the same things, those from one type usually can learn a decent amount of the other, that sort of thing... still, a small sigh, though like Ingo he doesn't sound particularly fussed overall. ] Obviously not enough, though. Oh well. Either I can or I can't. Verdict to be made further down the line than where we are currently at.