The most powerful dragon move is roar of time which can only be learned by dialga. otherwise it's Draco meteor
It's pretty much up to you. But I recommend a powerful move that is his type. Why? Well apparently if you use a move that's your pokemon's type, it becomes more powerful plus since you taught your nidoking a POWERFUL move. It becomes deadly.
The best grass type move - the powerfulest is frenzy plant which deals 150atk points and 90 accurcy
yeah shes most powerful
the most powerful trade was zimbabwe. I guess
its move is assurance
the most powerful physic move is Psycho Boost
The most powerful normal type move is Giga Impact
The most powerful rock type move is either rock wrecker and head smash
insidious
Psychic.
In terms of base power, the most powerful move is explosion, then self destruct, but they both cause you to faint after using them.
hydro pump
Magma Storm
Its eruption as the first powerful is blast burn.
Frenzy Plant
Psystrike