Ruling Damage boost and Flip attacks

[Soulero]

Hey

You must all think that this is a quite stupid question but when it comes to damage boosts such as the one from Nidoking when is the extra damage applied?

If I have Nidorino will it attack for "20xheads + 10" or "30xheads"?
Also does the ability stack?

Im sorry for asking such a stupid question but I would appreciate if anyone would like to answer me ^^

 

[King Arceus]

The ability does stack because it doesn't say that it doesn't. You apply the extra damage after any modifiers to the damage so it would be 20x heads + 10.~KA

 

[Soulero]

Thank you for your time ^^