I don't think it's about number of decks. I think it's about number of cards, and for that, I chose and cards.
I meant that those cards are only ever used in 1 or 2 decks, you don't see them ever anywhere else
e.g. only adrenaline in rush photon/frogs otherwise I never see adrenaline
the only
cards I ever see are Empathic bond and heal, occasionly staff and shield but really none others
The only
cards I see are vampires and devourers -- either for healing or denial, I rarely see any other darkness cards (except steal obv)
and the only water cards I ever see are squid, and I don't see it often.