mtg hero's path cards Sorrow's (Card) You may put that card on the bottom.) The Provider - Hero's Path

Obvious contenders are Snapcaster Mage and the like - creatures that accrue their value when entering the battlefield or in response to an opponent's attempt at a maneuver, and can then be used to counter a new threat later

Its also the first headliner card where Wizards just chooses to print it with all the optional extras

This is the kind of card that is absolutely tailor made for the format

Fiend Artisan Further pushing the Birthing Pod-on-a-body design, Fiend Artisan forgoes all that difficult addition and just lets you sac a creature and pay X to get a card with mana value X or less onto the battlefield

Tip: Try to sequence so you play Sram and then an aura immediately afterward in the same turn

It is also weaker against vigilance or dorks needed purely for defense as they only need pay the mana once.Overall this is a lower number of things than would sidestep a Doom Blade or more common black restriction