Pkm that might have Nasty Plot and still make somewhat sense:
Intelleon, Orbeetle, Noctowl, Thievul, Froslass, Xatu, Gengar, Noivern, Grimmsnarl, Hatterene, Gothitelle, Accelgor, Toxitricy, Polteageist, Ideedee, Rotom,
Probably unviable:
Corviknight, Obstagoon, Pangoro, Umbreon, Scrafty, Bisharp, Malamar, Grabbloct, Morpeko
I wouldn't mind if something like Flygon or Silvally were to get Nasty Plot. They could definitely need that to become more viable. I also hope Xatu and not Sigilyph get this move because almost everything Xatu does Sigilyph does it better...
That is... not at all what I thought the effects would be.
In any case, Dragapult just got scarier. Both of its STAB Max moves increase the power of its attacks.
Dragon lowers the target's attack unless you mean to say that dragon moves in general become stronger thrpugh dynamax.