In Premodern, its kind of agreed on, I think, that the best white and black cards are Swords to Plowshares and Cabal Therapy
When you cast a spell with the MTG Cascade keyword, you exile cards from the top of your library until you hit a spell with a lower mana value
D&D campaigns are (very often) all about powerful characters that take on evil doers to save the world, or at the very least a town or city, from destruction
Spell Pierce hits cards of any mana value and Flusterstorm is the best way to win a big stack battle thanks to storm, but Minor Misstep has some upsides too: it's a hard counter, so unlike Spell Pierce you don't have to worry about your opponent paying for it in the late game and resolving their spell and it can hit creatures along with spells, which is huge in a world where Ragavan, Nimble Pilferer is in one-third of decks
The Masamune is a nice card in Sephiroth decks specifically, but I'd rather just run a copy of Blood ArtistBlood Artist for the same effect with more consistency anywhere else
Blue can always draw a lot of cards, so it may not be the most exciting topic, but someone had to do it