There's not a more wholesome character we could think of to be on our side than Pooh
Not only do a number of characters, songs, and actions cause your opponent to Discard cards, but some even have abilities that give you a bonus for opponents having fewer cards in their hand than you
Cards like Force of Will, Fierce Guardianship, Pact of Negation, and Force of Negation let you stop game-winning plays while tapped out, which is perfect for protecting your own combo turn or stopping someone else's
It only costs one red mana to cast, and you can give it dash for one red and one generic mana so that it has haste
These, too, are desirable because of their power in the game and because they're "rare" cards
I think making it even just a bit cheaper wouldve been an amazing way to use this sets crossover to introduce Magic players to D&D, or vice versa