Oath of the Ancient Wood
Most enchantment-matters designs reward you for what is already on the battlefield; this one rewards every fresh arrival, including its own, so the counter is a small grant that compounds with how many enchantments you can chain into play over a game. The growth is incidental on any single trigger and meaningful only across a board built to keep enchantments coming: auras, totems, the cheap permanents that fill out an enchantment-heavy shell. That structure gives the card its character. It is not a finisher and never pretends to be; it is the accumulator that turns a critical mass of enchantments into a slowly widening lead on the board, one +1/+1 counter at a time. Note that the trigger does mandate a target creature: the "may" only governs whether the counter actually lands on resolution, not whether you choose to target, so if your opponent's creatures are the only legal targets you are still forced to point at one, with whatever targeting-based consequences that carries. When you control the only creatures, you keep full discretion over placement and can decline a counter rather than waste it on something already dying. Read alone it looks like a minor value engine, and at one trigger it is; read as the anchor it was built to be, every enchantment you cast becomes a quiet investment in your creatures.
