Luke, Inventor Supreme

Artifact spells you cast cost {2} less to cast.
{1}{w}{u}{b}{r}, {t}: Search your library for an artifact card, put it onto the battlefield, then shuffle your library.
{1}{w}{u}: Target artifact gains "This creature has hexproof as long as you control a creature named Luke, Inventor Supreme"
{b}{r}, sacrifice an artifact: Deal 3 damage to any target.