card store mtg $1 Dollar Repacks and open gorgeous Borderless cards—plus you can find a foil in every booster Magic: The Gathering Singles, Collections

Soul Transfer It is a slow but situational Heros Downfall and the good thing is the chance that you can choose both by having an artifact & an enchantment in play

Tormods Crypt doesnt cost anything to cast, Soul-Guide Lantern exiles a card upon ETB, and Unlicensed Hearse is a graveyard-hate card that can turn into a threat

Note there might be a bit of a trick question here

If the game stretches out, you might even be able to drop the Cordial Vampire and then burst-kill someone out of nowhere, thanks to how well it plays with Kalastria Highborn and Blood Artist when fueled by zero-mana sacrifice outlets such as Viscera Seer, Stromkirk Condemned, and Bloodthrone Vampire

I put free in quotes because it is still costing you a card to do this and, a lot of times, a card is more valuable than anything else