Buff Card was first released in the set March of the Machine Jumpstart Front Cards, illustrated by Filip Burburan
In media interviews before the panel, the game designers spoke about the imperative they felt to get things right to design cards that felt authentic to the games and series, cards that felt meaningful to the fans, instead of just constructing them based on business goals
If you run Shark Typhoon, this gets even better
It also has two abilities, the first of which is Clever Swap, which lets you draw and discard a card whenever the character has quested
Going straight from 3 mana to 6 the next turn after you play a land lets you rocket out some terrifying beaters like Hellkite Tyrant and Ancient Copper dragon quite early, and you can run blacks cheap graveyard tutoring like Buried Alive or Entomb to gain easy access to a variety of threats