Amber, the Mechromancer

Improvise. When you cast this card, return target
artifact card from your graveyard to the
battlefield with converted mana cost X or less.
Whenever an opponent casts a spell you may pay
{c}{u}. If you do, return target noncreature
artifact card from your graveyard to the
battlefield.
Sacrifice three artifacts: Counter target
nonartifact spell.