You can't untap your permanents more than once in a single untap step
Simple cantrips like Opt and Preordain become powerful card draw spells, and since Matoya doesnt have a once per turn restriction, you can draw cards throughout your turn with effects like Search for Azcanta, Retreat to Coralhelm, and Palantr of Orthanc
An easy indication is the price difference between a booster of either set
Kuja, Genome Sorcerer // Trance Kuja, Fate Defied This Rakdos four-drop is legendary and a 3/4 size and then in your end step you'll make a free Black Wizard with the normal stuff and then yay for that - good stuff
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control
Well, why not get some friends together and either crack six packs of CLB each to build a deck with, or even draft the packs between each other and then pod up for Commander gameplay