Simic Ascendancy is a rare Enchantment card from Bloomburrow Commander (BLC), collector number 260. Current market price: $1.22, TCGplayer market prices via Scryfall.
{1}{G}{U}: Put a +1/+1 counter on target creature you control. Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on this enchantment. At the beginning of your upkeep, if this enchantment has twenty or more growth counters on it, you win the game.