Summoning Materia

Green has printed top-of-library card advantage before, but almost always with a fixed clause: reveal on your upkeep, or cast the top card only if it's a creature. This piece of Equipment collapses two of green's favorite engines into one attachment. The library-vision effect (looking at the top card whenever you like, then casting creatures from it) turns your deck into an open hand of monsters, so every draw step is a known quantity and every cast off the top thins the library toward the next threat. The equip cost is where the tension sits. Equipment survives its creature dying, which normally makes it resilient, but here the two most valuable clauses (top-of-library casting and the mana-producing tap) only function while it's attached, so a removal spell on the equipped creature doesn't kill the artifact, it just switches the engine off until you pay to reattach. The stat bump is the pedestrian part; the vigilance and the ": Add " are what make the wearer both an attacker and a ramp piece, letting it swing and still pay toward the next creature you already know is coming. The whole package rewards a board wide enough that losing one bearer never strands the card, which is the quiet cost green pays for reading and casting off the top at once.