I love this.
I get to play against decks with Anubis, my original favourite card. I don't think I had even seen one in PvP for a looong time, and definitely not 5. (Hi Shantu!)
And it was awesome.
But it can't really compete with decks who get cards like Immolation/Quantum Pillar/Supernova/Phoenix/ ect.
Meaning that in the end, a person who put a mega-super-Hey!OPPPP!-uggh-rainbow up one day, then the next day returns with a nice profit for absolutely nothing rolls the oracle and sees themselves winning...schoedingers cat (would be a fun deck to play against too...) might just choose to forget to update their deck.
Meaning in the long run, we get a lot of overpowered decks trolling around, and losing the variety which we love so much.
Overall, what I am suggesting is really some incentive to change decks. Maybe a 25 health loss every day, until it reaches 50 - or a small bonus for changing decks, I dunno. Plus, like the oracle, it will get people coming back to the game over and over again, which has to be pretty good from a developers point of view.
Again, great work, I love, just... me being a dick about things.