Aphelios

Artifact spells you cast cost {1} less to cast.
As Aphelios enters the battlefield, you may reveal
any number of other artifact cards from your
hand. Aphelios enters the battlefield with a
+1/+1 counter on it for each card revealed this
way.
Whenever another artifact enters the battlefield
under your control or another artifact you control
leaves the battlefield, you may pay {3}. If you do,
target player loses 3 life and you gain 3 life.