Mechanics arose from visualizing how two armies of creatures would battle each other, rather than creating mechanics and then fitting them into the Magic world. These two points of departure were later codified in design terms as top-down versus bottom-up
Arvinox, the Mind Flail Arvinox, the Mind Flail is a List rebrand of Mind Flayer, the Shadow from Secret Lair X Stranger Things
It doesnt steal cards itself, but there are plenty of effects that allow you to do so
Made to ward off the Grim Captain and silence the lure of undeath
This lets us set up some charming plays where we cast Kiora Bests the Sea God for a surprise 8/8 blocker or play Virtue of Persistence right before our turn starts to minimize the amount of time our opponents have to answer it before we get the first trigger
This mechanic is another one that people can check off of their wishlists, as it is something that Magic Head Designer Mark Rosewater says players have consistently requested