Vial Smasher the Fierce would prove demonstrably powerful, with over 5000 decks from his top 3 Partner picks alone, but who could contend with This commander is practically synonymous with cEDH
It puts the card directly into your hand, which circumvents drawing restrictions such as Notion Thief and Narset, Parter of Veils - and with that also doesnt count towards other catch up cards like the Smugglers Share mentioned earlier
So, essentially, extra turn spells have a rate (in the modern era) of costing a variable five mana, a la Time Warp
Activated Sleeper was in the Dominaria United Set and Collector boosters, right
If Pyrotechnic Performer could hit creatures or planeswalkers it might start a conversation at four mana
Contents: 15 Magic: The Gathering cards 4 Traditional foil common cards 3 Traditional foil uncommon cards 1 Traditional foil retro frame basic land 2 Non-foil Booster Fun common or uncommon cards 1 Traditional foil Booster Fun common or uncommon card 1 Traditional foil default treatment rare or mythic rare card 2 Non-foil Booster Fun rare or mythic rare cards 1 Traditional foil Booster Fun rare or mythic rare card (In less than 1% of Collector Boosters, this is replaced with a serialized double rainbow foil movie poster Edgar Markov.) 1 Traditional foil double-sided token