The most popular ones, as you may have guessed by now, only see play in Commander, but the few that see competitive play are powerhouses on their own
5 loyalty Player 3 - During his or her upkeep, Player 1 uses Teferi, Master of Time to use its first ability to +1 and Loot
If you use your marked deck in the right way, with well-constructed magic and with good audience management, then in practice your spectator will never even suspect your deck, or ask to examine the cards
Then there are cards like Aya of Alexandria, Kassandra, Eagle Bearer, Edward Kenway and Adwal, Breaker of Chains
Set and Draft Boosters will have to wait, as those require a whole new set of tables and calculations