Briarblade Adept is a common Creature — Elf Assassin card from Commander Legends (CMR), collector number 111. Current market price: $0.19 (foil $0.26), TCGplayer market prices via Scryfall.
Whenever this creature attacks, target creature an opponent controls gets -1/-1 until end of turn. Encore {3}{B} ({3}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)