Midnight Angel Armor

Most Equipment asks you to spend a card getting a creature onto the battlefield before the gear does anything; strap this to nothing and you have paid five mana for a static bonus and a dead artifact. This one solves its own dependency by making the body it wants on the way in: a 1/1 token appears and the Equipment latches on immediately, so the floor is a 4/4 flier with vigilance for five mana that leaves an object on the field even after the wearer dies. That last part is the quiet strength of the design. Kill the flier and the armor stays, ready to move to the next creature for the equip cost, which turns a single removal spell into a speed bump rather than a two-for-one. Vigilance stacked onto flying is a deliberate pairing: the equipped creature holds the air as a blocker and still swings each turn, so the +3/+3 does double duty on both halves of the combat step. It is the auto-attach template that a handful of Equipment before it have used to dodge the standard trap of being a do-nothing until you find a target, and it commits fully to that idea by baking the creature and the attach into one arrival trigger.