OCG Structures, this Duel Disk has an additional slot as an Extra Monster Zone that opens from the edge of the blade where to summon and place Monsters from the Extra Deck
Theres also a way to make a storm combo at the end of an opponents turn where you cast a bunch of cantrips, pay a lot of life, and strike back with a surprise army of 5/5s or greater
For example, the Tarot deck, originally for competitive card games, later morphed into a tool for fortune-telling
Goldvein also has Vigilance, Trample, and Haste, making it a scary card to see played, especially when the X cost is so easily raised by the Commander
And as an enchantment, its much harder to deal with than a creature
Consider a single Robin Hood Timely Contestant as a late-game bomb