Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life. {T}, Sacrifice another black creature: Draw a card.

Menace, lifelink Whenever a Knight you control deals combat damage to a player, put a +1/+1 counter on that creature and create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Flash When this creature enters, draw X cards, where X is the number of creatures that died under your control this turn.

Menace Whenever a nontoken Knight you control dies, each opponent loses 1 life and you draw a card.

{B}, {T}, Discard a card: Add {B}{B}{B}.

Menace {1}{B}, {T}, Pay 1 life: Create a Treasure token. {2}{B}: Target creature gets +2/+0 until end of turn. If mana from a Treasure was spent to activate this ability, that creature also gains deathtouch until end of turn.

Sacrifice a creature: Add one mana of any color.

Flash When this creature enters, target Knight gains deathtouch and lifelink until end of turn.

Lifelink When this creature enters, you may sacrifice another creature. When you do, destroy target creature an opponent controls. When this creature dies, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Menace Whenever this creature deals combat damage to a player, if it has fewer than four +1/+1 counters on it, put a +1/+1 counter on it. Then if it has exactly four +1/+1 counters on it, search your library for a card, put it into your hand, then shuffle.