By all means put a card down in front of me or for that matter put down your deck. Yep that's right put it down on the table.
Because it exists online does not mean that it is real.
Holding something digitally isn't the same as holding something physically in your hand.
I can have a virtual reality copy of an Angus trim longsword in my hand....
However you cannot use that to train in the physical world. You might be able to use it to train in the virtual world when they get the technology going.
But yes made up cards that don't exist are not real...
Lool yes on that front, i get you, they are not real actually....
It's totally cool idea but there are some practical drawbacks