Obviously, when the only cycling card is a reprint, no innovation is going on
Its a deck where I use Duress, and you can see the icon: When I click that icon, you can see all the printings I have displayed
What's done is done, just know that putting Mana Crypt in your casual coin-flip deck meaningfully raises the power level of your deck.
The Backup mechanic on Voldaren Thrillseeker seems like it could result in some pretty unexpected combos depending on what abilities are linked to it for example, just within this set, you can use it with the previously revealed Yargle and Multani to deal 20 damage
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature. Its a really useful way of keeping your mana investments a bit safer than they would normally be