[humor]
Silly people.
The game runs on card advantage not on quanta efficiency. Sure Dagger | Dirk is 3|5 attack for 0 quanta, however it is merely 3|5 attack for 1 card. Even the UP Crimson Dragon | Ruby Dragon is better than that. The true OP card is Golden Nymph | Golden Nymph. It looks like a mere 6|7 attack for 1 card but it gives you an extra card per turn. 6|7 attack for -4 cards is so powerful that it cannot be calculated with the standard Benefit/Cost ratio (6/-4 = -1.5).
[/humor]
Aww, you break the jokes...
Hey, I am not the one that divided by a negative number.
... Oh, wait I did. The Golden Nymph made me do it.

*while the Nymph is not looking* Quick NERF Golden Nymph before they conquer EtG!
*nymph returns* I meant turn them into NERF so they resist damage. Yes, that's what I meant.