It's expected to feature the first 151 Pokemon, including Kadabra
We can only assume that the monsters from Yu-Gi-Oh
Creature - Kraken Kederekt Leviathan When this creature enters, return all other nonland permanents to their owners' hands
1 Urza, Lord High Artificer Works Well With Any Artifact Build 9,488 Decks on EDHrec.com Urza, Lord High Artificer is the most popular mono-blue commander, and Commander players should be aware that playing such a deck will often make them a huge target, especially in more casual groups
If card sizes varied, protecting your beloved cards would be a minefield, as you'd need a whole array of different-sized folders, card sleeves, and deck boxes to accommodate them all