Karn, Father of Mirrodin

When Karn, Father of Mirrodin enters play, you
may reveal an artifact from outside of the game
and add it to your hand. If you do, you lose life
equal to its converted mana cost.
Sacrafice Karn, Father of Mirrodin:
Put an artifact from your hand into play.
This corruption has blighted mirrodin long enough.
My mistakes will be corrected at all cost.