Commence the Endgame is a rare Instant card from Aetherdrift Commander (DRC), collector number 38. Current market price: $0.24, TCGplayer market prices via Scryfall.
This spell can't be countered. Draw two cards, then amass Zombies X, where X is the number of cards in your hand. (Put X +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)