Some of these copying cards, like Blade of Selves and Delina, Wild Mage are definitely worth keeping an eye on, while others, like Orthion, Hero of Lavabrink, have already shot up in price
Mayhem is pretty similar to madness, only that it forces to player to follow timing restrictions
It boils down to this: give me less battle royale and more TCG.
This recent round of previews showed off some versions of Tifa, Kain from Final Fantasy IV, Squall, Rinoa, and Angelo from VIII, Zidane (with one version being an alternate for competitive powerhouse Ragavan), and Vivi, and even a couple of versions of Firion from the divisive second entry
The payoff is that your creatures all get double strike, which is a really huge swingy bonus to give
Not only is it incredibly fast, but the scanner can capture multiple cards at once