fight mtg cards as One (Card) Return each card chosen this way to the battlefield under your control Back To The Basics -

Although most commons throughout MTGs history are basically worthless as trade items, with pennies of value at most, the cards featured on this list are worth more than $7 a piece and a high point at $60

When you spend this mana to cast an instant or sorcery spell with mana value 3 or less, you may exile that spell instead of putting it into its owner's graveyard as it resolves

Saved by the Shell

Even in EDH, you can go off when you have Professor Onyx in play and cast or copy a bunch of instants or sorceries

If you really want to lean into the mill plan, Rings of Brighthearth will copy Persistent Petitioners ability for a small mana investment every time

Throw in some Trample and Haste, and this card's 72-dollar price tag seems a bit less unreasonable