Sothera, the Supervoid is a mythic Legendary Enchantment card from Edge of Eternities Promos (PEOE), collector number 115p. Current market price: $2.05 (foil $3.20), TCGplayer market prices via Scryfall.
Whenever a creature you control dies, each opponent chooses a creature they control and exiles it. At the beginning of your end step, if a player controls no creatures, sacrifice Sothera, then put a creature card exiled with it onto the battlefield under your control with two additional +1/+1 counters on it.