PlusPower (and the like) on attacks with no printed damage number

[Guybrush]

PlusPower... as far as I know, latest text for the card reads as follows:

"Attach PlusPower to 1 of your Pokémon. Discard this card at the end of your turn.
If the Pokémon PlusPower is attached to attacks, the attack does 10 more damage to the Defending Pokémon (before applying Weakness and Resistance)."

It makes no reference to the attack having to do damage in the first place for the effect to work, but it does say "more" damage which might imply that it has to do damage in the first place, so I'm not sure... will attacks that normally have no printed damage number next to them do 10 damage to the defending pokemon when PlusPower is used?

and I assume it'll be the same answer, but what about Black Belt? "During this turn, each of your Active Pokémon's attacks does 40 more damage to your opponent's Active Pokémon"

thanks

 

[PokePop]

You're correct that the word "more" is the critical word.

You can't do "more" unless you've done some to start with.

But don't focus on the big printed number to the right.
There are some attacks that let you choose what Pokemon to target and they may not have any damage number written in big text.
But as long as you are doing damage (not placing damage counters) to the Active Pokemon, then Plus Power (and Black Belt) will add to that damage.