Cards like Budew completely stop the deck from functioning, and it has horrible matchups into decks like Raging Bolt ex and Gardevoir, both of which are dominant meta threats currently
Maid Marian works because she throws off the opponent's math
Certain spells in Magic have a unique keyword called suspend, which acts as an alternate casting cost, often times cheaper than its regular one, at the expense of having to wait a few extra turns to finish casting it
In fact, it just lasts one turn
The two join Karlach and Astarion as BG3 characters who have previously been part of Secret Lair
Kewl Tune B2B would fit best in a Synchro-heavy combo deck that plays many Tuners and can consistently make Level 10 Synchrosespecially decks like Synchron/Junk-Doppel, Mannadium, or certain Resonator variants that want extenders in the GY and can capitalize on reactive Synchro plays during the opponents turn