So, I've heard of a new Ghost type attack called Trick or Treat. It's like Soak. It changes the enemy type to Ghost.
This sounds a lot more useful than Soak, though. Where Soak would change an enemy into a type resistant to your attacks, Trick or Treat, which is almost certainly a Ghost exclusive move, means an enemy becomes weak to your STAB.
You also rob an enemy of STAB at the same time, as well as any other weaknesses, resistances, and immunities they'd normally have.
If it's real, it's a very useful support move, and every Ghost that can get it should not be without it.