Regarding drawing cards from abilities/supporters

[Zaymont]

Friends have been discussing so to confirm it all.
If an ability or supporter etc. Stats you to draw any cards in deck while you do not have any, you cannot activate the card?
So things like Greninja, Revavroom, Bibarel, Professor Sada's Vitality you could only activate with at least one in deck?
As well as Draw until X cards in hand is fine even if you can't meet the specified amount due to decking out?

 

[PokePop]

Generally you have to be able to do something (other than the cost) in order to use an Ability/play a card.
There are exceptions, like if the effect is blocked by another effect. But you have to have a valid target.
If there are no cards in the deck, you have no valid target