The damage dealed by Mismatched skills

Hi, guys, I have been thinking about this question for a while.

Hypothetically , if there is a Skelly.
Cunning : power 60
Ambush: power 35-- always critical, make it 70
Aurora Borealis: power 120 ( or some other magical move that has a 120 atk)

If the opponent is plant type, I bet aurora will deal more damage.

What if the opponent is for example, earth or physical .

Which skill out of the three will deal the most damage? Since aurora is mismatched on Skelly, its damage will be lowered, but how to calculate How much is lowered?

thanks guys, when it comes to number crunching, Aiya....

Cunning will do the most dmg, but attavks last ;P

Cunning will do the most dmg, but attavks last ;P

So cunning will always go last, regardless of speed?

Cunning will do the most dmg, but attavks last ;P

So cunning will always go last, regardless of speed?

Correct since vert is slow might be good idea to put cunning on vert