Shen the Twilight Eye

Ninjutsu {u/b}{u/b} ({u/b}{u/b} Return an unblocked
attacker you control to its owner's hand: Put this
card onto the battlefield from your hand tapped
and attacking.)
Whenever Shen the Twilight Eye deals damage to
an opponent, you may search your library for an artifact
or sorcery card and put it into your hand.
Whenever you cast an artifact or sorcery spell,
you may return Shen the Twilight Eye from the battlefield to your hand.