Lorna Dane, Polaris

Flying
X-Trait--Whenever you cast your second spell
of the turn, you may destroy target artifact,
Lorna Dane, Polaris deals X damage to target
creature equal to it's converted mana cost.
{2}{r}{r},{t}Gain control of target artifact until
end of turn.
{x}{r}{r}{t}Destroy target Artifact with
Converted Mana Cost X.