Crazy Diamond, Goldheart

Stand - Once per match, if you control a Legendary Creature or Planeswalker, you may cast this card from your library or graveyard.

{x}{w/u}{t} - Return target artifact with converted mana cost X or less from the graveyard to the battlefield under your control. If X is 3 or more, Crazy Diamond, Goldheart gains +X/+X while target artifact is in play.