Arcane Nullifier X-21 is a rare neutral minion card that belongs to the "Goblins vs. Gnomes" set, which was released on 08.12.2014 and is one of initially 123 cards. The artist of this card was Zero Yue, who also made 4 other artworks for Hearthstone.
The flavor text of the card is the following: There was some hard talk between gnome magi and engineers about inventing this mech.
The card is on average to memorize with 86.6% of correct quiz questions.
