msem-instigator

Sacrifice a creature: Rapacious Demon gets +1/+1 and gains flying until end of turn. Activate only as a sorcery.

Rattlecage Terror enters tapped.
{1}{B}: Return Rattlecage Terror from your graveyard to your hand. When you do, another target creature card with mana value 3 or less in your graveyard gains this activated ability until end of turn, except it costs {1} more to activate.

Enchant creature
When Ravage of Moments enters and at the beginning of your upkeep, put a -1/-1 counter on enchanted creature.

Whenever a creature you control dies, each opponent discards a card.
Revive {6}{B} ({6}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever Ravaging Tyrant enters or attacks, each opponent loses 3 life, discards a card, and sacrifices a creature or planeswalker.

Whenever Ravencaller or another creature enters from your graveyard, create a 1/1 blue Bird creature token with flying.

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Ravenous Grue enters with a menace counter on it.
{5}{B}{B}, Remove a menace counter from Ravenous Grue: Destroy target creature.

When Ravenous Rats enters, target opponent discards a card.

Lifelink
When Ravenous Tarwurm enters, you may have it consume. When you do, destroy target creature with toughness 3 or less and you gain 3 life. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

When Razorshell Marauder enters, you may sacrifice a land or exile a land card from your graveyard. When you do, target creature gets -1/-1 until end of turn and can't block this turn.

Scry 2, then draw two cards. You lose 2 life.

As an additional cost to cast this spell, sacrifice a creature.
Look at the top X cards of your library, where X is the sacrificed creature's power. Put one of those cards into your hand and the rest into your graveyard.

Whenever another creature you control dies, target player loses 1 life and you gain 1 life.
{1}{B}, Sacrifice a creature: Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

Enchant creature
Enchanted creature has deathtouch and “When this creature dies, create a 2/2 black Demon creature token.”
{1}{B}, Exile Reaping Mask from your graveyard: Create a 2/2 black Demon creature token.

As an additional cost to cast this spell, sacrifice a creature.
Return two target creature cards from your graveyard to your hand.

Lionize {1}{B} ({1}{B}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following abilities until end of turn. You may cast this card on a later turn from exile.)
Flying, lifelink
Whenever this creature deals combat damage to a player, remove all counters from target permanent they control or protect.

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Return target creature or planeswalker card from your graveyard to your hand. If this spell's tithe was paid, return that card to the battlefield instead.

{2}{B}{B}, Exile Reclusive Augur from your graveyard: Return another target creature card from your graveyard to the battlefield. Activate only during your turn.

As an additional cost to cast this spell, pay {2} or sacrifice a creature.
Menace

Return target creature card from your graveyard to your hand.
Draw a card.

Whenever Recurring Abomination deals combat damage to an opponent, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.
{4}{B}{B}: Return Recurring Abomination from your graveyard to the battlefield tapped.

When Red Flower Assassin enters, destroy target creature.
Revive {5}{B} ({5}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Target player sacrifices a creature. Then you gain 3 life if that player doesn't control any creatures.

Target player discards two cards.
Flashback {4}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)