Found a mistake for Mega Gengar...

[Derpghost]

So, I was preparing a mega-gengar set in X&Y, and found a set that recommended Sludge wave, whitch Gengar can't learn. Could someone please fix this?

 

[Lumari]

Gastly can get Sludge Wave from the Dream World, and in gen 6 an event Gengar with Sludge Wave was given out as well, so the set is fine as is. If you're playing on the cart games rather than on the simulator then you'll probably have to settle for Sludge Bomb though yes.

For future reference, small fixes like these don't need their own thread, but they go here: http://www.smogon.com/forums/threads/small-objective-changes-typos-poor-wording-etc.3489981/