Tezzeret the Seeker
From Mythic Edition set
Tezzeret the Seeker
Legendary Planeswalker — Tezzeret
+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.