It featured in some of the earliest decks in the game, it was a pivotal piece of the Sligh deck which essentially acted as the foundation of the mono red aggro archetype, and its presence has been significant in Modern from the first day of the format as it has featured in many of the formats best decks from Zoo to Splinter Twin to Jund
Equip abilities you activate cost less to activate
While Batterskull has long been the best friend of Stoneforge Mystic, the printing of Kaldra Compleat added an even deadlier threat to the Artificers toolbox
Nasty quartet for going wide brews like Kindred above, aggro, Hate Bears, Azorius flyers, Dimir or Esper Faeries, and loads more
Not even extremely rare cards like Black Lotus are in this level, since there are a couple copies around the world