Viridian Lorebearers

The pump scales off the wrong side of the table. Most variable buffs in green read your own board (creatures you control, lands, the size of your team); this one counts artifacts your opponents control, which makes it a strange hybrid of removal-adjacent tech and a finisher whose ceiling you do not own. The design logic is pure block-context: this came from an era when artifacts saturated the format, so a green creature that converted the enemy's affinity engine, Myr swarm, and equipment pile into one oversized attacker was answering a specific arms race rather than offering a generic combat trick. The friction is everywhere else. At four mana to fire plus a tap, the activation eats your whole turn's mana and the body each time it goes off, so even at instant speed it never plays like an ambush: the ability sits on the board for the opponent to read and play around, and the size of the buff is dictated entirely by what they have chosen to commit. Against an artifact-light opponent it does nothing but stand there as a 3/3, which is the honest tax on an ability that can read +6/+6 or larger against the right deck. It is a sideboard answer disguised as a maindeck creature: an Elf that asks the opponent to have committed to artifacts before it earns its mana, and stands idle when they have not.