Creature removal can respond to the copied Electroduplicate, removing the Dualcaster Mage, and making Electroduplicate fail to resolve due to a lack of targets
Demonic Tutor As powerful and efficient as all the tutors are that weve looked at today, none holds a candle to the original
The Hot List Lutri, the Spellchaser For years, Lutri was the ultimate what if card, famously banned in Commander before it even saw a prerelease
They do function as normal enchantments, so if they are in a deck they can be drawn and cast normally, although as they specifically only affect Commanders, its very unlikely youll ever encounter one in any other format
Most of those just have the ability to lose defender and attack
Throne of Eldraine The first set with collector boosters, the best and biggest things you could open from the Throne of Eldraine collector boosters were The Great Henge, showcase Brazen Borrower, and showcase Oko, Thief of Crowns