msem-instigator

Whenever Qalami Barbarian attacks, you may discard a card. If you do, it gets +1/+2 and gains menace until end of turn.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Target opponent sacrifices a creature or planeswalker.
3 | That player also sacrifices an artifact or enchantment.

When this creature dies, put a -1/-1 counter on up to one target creature.

Whenever Quick-Witted Slayer deals combat damage to a player, you draw a card and you lose 1 life.

Destroy target creature or planeswalker. Create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

Deathtouch
Whenever a creature dealt damage by Rabid Rodent this turn dies, put a +1/+1 counter on Rabid Rodent.
{2}, Remove a +1/+1 counter from Rabid Rodent: Regenerate Rabid Rodent.

Enchant creature
Enchanted creature gets +3/-3.

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Return target creature card from your graveyard to your hand. Then if this spell was kicked, return another target creature card from your graveyard to your hand.

When Ragantiar enters, mill five cards.
{3}{B}, Sacrifice a creature: Return target creature card with power X or less from your graveyard to the battlefield, where X is 1 plus the sacrificed creature's power.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you attack, add a quest counter.
1, 2 — Mill two cards.
3 — Return up to two target creature cards from your graveyard to your hand.
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Vanishing 5 (This creature enters with five time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever you remove a time counter from Rallios, create a tapped 2/2 black Zombie creature token.

Menace
When Rallios Unleashed enters, create a 2/2 black Zombie creature token.
Whenever Rallios Unleashed deals combat damage to a player, create a 2/2 black Zombie creature token for each creature card in your graveyard.

When this creature enters, for each kind of counter on target permanent, put another counter of that kind on it or remove one from it.

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.