: Destroy target artifact. Hoard-Smelter Dragon gets +X/+0 until end of turn, where X is that artifact's converted mana cost.
1/1/2011 If the targeted artifact is an illegal target by the time the activated ability resolves, the ability doesn’t resolve. Hoard-Smelter Dragon won’t get the bonus.
1/1/2011 If the mana cost of a permanent includes , that X is considered to be 0.
7/1/2013 If the activated ability resolves but the targeted artifact isn’t destroyed (perhaps because it has indestructible or it regenerates), Hoard-Smelter Dragon will still get the bonus.