Willowdusk, Essence Seer is a mythic Legendary Creature — Dryad Druid card from Commander 2021 (C21), collector number 333. Current market price: $6.34, TCGplayer market prices via Scryfall.
{1}, {T}: Choose another target creature. Put a number of +1/+1 counters on it equal to the amount of life you gained this turn or the amount of life you lost this turn, whichever is greater. Activate only as a sorcery.