msem-instigator

Whenever an enchantment you control enters, create a 1/1 colorless Construct Actor creature token.
Token creatures you control have vigilance.

When Radiant Rebuker enters, exile target nonland permanent an opponent controls until Radiant Rebuker leaves the battlefield.

Trample
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Whenever Rage-Fueled Adventurer attacks, you may have it fight target creature you don't control.

Flying, haste
{3}{R}{R}: Return Rageborn Phoenix from your graveyard to your hand. If you do, it deals 1 damage to any target.

Whenever you cast a noncreature spell, Rageborn Pyromancer gets +1/+1 until end of turn.
{1}{R}: Rageborn Pyromancer gets +1/+0 and gains flying until end of turn.

When Raging Restitched enters, you may sacrifice a creature. When you do, Raging Restitched deals damage to target creature or planeswalker equal to the sacrificed creature's power.

Flying
When Rahstahde Persecutor enters, you may pay {2}{R}. When you do, it deals 4 damage to target creature.

When Rahstahde Pledge enters, you may return target instant or sorcery card from your graveyard to your hand.

Revive {3}{G} ({3}{G}, 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.)

When Raikai Seafarer enters, you may search your library for up to three cards named Raikai Seafarer, reveal them, put them into your hand, then shuffle.

Haste
When Rainy Night Lovers enters, look at the top four cards of your library. You may cast a red instant or sorcery spell with mana value 1 from among them without paying its mana cost. Then put the rest on the bottom of your library in any order.

Trample
Art of war — At the beginning of your end step, if Raiun Bay Admiral dealt damage to an opponent this turn, put a +1/+1 counter on each other creature you control.

Art of war — At the beginning of your end step, if Raiun Bay Scourge dealt damage to an opponent this turn, gain control of target artifact or enchantment until Raiun Bay Scourge leaves the battlefield.

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.

Indestructible
Battalion — Whenever Rallios, Heir to the Evil One and at least two other creatures attack, creatures you control get +1/+0 and gain double strike until end of turn.

Flying
When Rallywing enters, creatures you control get +1/+1 until end of turn.

Whenever Ram Wrangler attacks, until end of turn, gain control of target creature defending player controls with power less than or equal to the number of creatures in Ram Wrangler's pack. Tap it. It's attacking defending player. (Two or more creatures you control with equal power are in a pack.)

At the beginning of your upkeep, mill two cards.

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.

First strike
When Rapacious Rattler enters, choose one or two targets you don't control. It deals 2 damage to the first and 1 damage to the second.

Flying
When Rapacious Regent enters, you may sacrifice another creature or artifact. If you do, Rapacious Regent deals 3 damage to any target.

Menace
Discard a card: Target artifact creature you control salvages Rappel Liner. Activate only if Rappel Liner is in your graveyard and only as a sorcery. (Exile this card until that creature leaves the battlefield. When that creature deals combat damage to a player, return a card it salvaged to your hand.)

When Rat King enters, create two 1/1 black Rat creature tokens with “This creature can't block.”
Whenever Rat King or another creature you control dies, each opponent loses 1 life and you gain 1 life.

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.

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