Special thanks to Maxwell Lee, John Nelson, and John Nevill for supplying detailed information about the Marketing Variation of Ivy Pikachu
Abyss Proxy Shop offers premium Blood for the Blood God
It also scales poorly with cEDH where most leaders are very cheap, so your foe may not want to discard their hand to draw a single card from their Isamaru, Hound of Konda or two from Baral, Chief of Compliance
Thus, the idea for my HeroClix Database came into being
There are implications of both strict superiority and efficacy around casting costs in both examples
There's a ton of cards to check out, but as head designer Mark Rosewater told a group of journalists at a special press preview event attended by Polygon, this is just the beginning of an even bigger team-up