Proft, Sinister Mastermind is a uncommon Legendary Creature — Human Rogue card from Reality Fracture (FRA), collector number 235. Current market price: $0.14 (foil $0.27), TCGplayer market prices via Scryfall.
Threshold — You can't cast this spell unless there are seven or more cards in your graveyard. Menace {B}, Discard this card: Target creature gets -3/-1 until end of turn.