mtg deals damage equal to cards in hand Rules Text: deals, damage, to, target, player, equal, to, the, number, of, cards, in, that..., 9 cards Rules Text: damage, you control,

In a deck that can go wide on the board, as Knights certainly can, this ability is incredibly dangerous, and can easily finish an opponent off in conjunction with other board-buff effects such as History of Benalia

If Primeval Spawn would enter the battlefield and it wasnt cast or no mana was spent to cast it, exile it instead makes it so you cant Reanimate, Sneak Attack or Polymorph it into existence and this design choice feels very deliberate

They always advertise MTG reprints in the description, but only show Bicycle playing cards in the pictures

The name is slang for sacrifice decks, and derives from the nickname for an old Standard deck using cards like Falkenrath Aristocrat and Cartel Aristocrat