msem-instigator

Flash
Enchant creature
When Roar of the Wilds enters, enchanted creature gets +3/+3 until end of turn.
When enchanted creature dies, create a 1/1 green Saproling creature token.

({T}: Add {U} or {R}.)
Roaring Cascade enters tapped.

{1}{R}: Roaring Dracowyrm gets +2/+0 until end of turn. Activate only once each turn.

Enchant creature
Enchanted creature gets +2/+1 and is a black Zombie in addition to its other colors and types.

Discard Robocamel: Create a Food token. Activate only as a sorcery. (It's an artifact with “{2}, {T}, Sacrifice this artifact: You gain 3 life.”)

When Rod of Marble Row enters, you may return target creature to its owner's hand.
Equipped creature gets +1/+1.
Equip {1}

Choose one —
• Destroy target artifact.
• Target creature gets +2/+1 and gains first strike until end of turn.
Kindle 2—{3}{R} ({3}{R}, Exile this card from your graveyard: Create two 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

Deploy 2 (As this enters, you may tap any number of other creatures you control with total power 2 or more.)
When Rogue Groundskeeper enters deployed, exile up to two target cards from a single graveyard.

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature deals combat damage to a player, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Flash
Flying
Romantic Wisp can block only creatures with flying.

Flying
When Rooftop Robber enters, another target Pirate or Rogue you control gets +2/+0 and can't be blocked this turn.

Choose one —
• Counter target spell unless its controller pays {2}.
• Create a tapped token that's a copy of target token you control.

Defender
As long as you control an enchantment, Rooted Cavalier has vigilance and can attack as though it didn't have defender.

{T}, Sacrifice Rootshambler: Untap all basic lands you control.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

When Roseblood Hart enters, choose one —
• Destroy target artifact.
• Create a Treasure token.

Instant, sorcery, and enchantment spells you cast cost {1} less to cast.

Rosesworn Knight gets +1/+1 as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

{6}: Create a 1/1 black Worm creature token.

Rot-Sand Ruins enters tapped unless you control another Desert.
{T}: Add {B} or {G}.

When Rotfeeder Slime dies, you gain 2 life for each creature card in your graveyard.

{2}{G}: Rotted Kalak gains indestructible until end of turn.
Revive {3}{B} ({3}{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.)

Enchant creature
{X}{B}: Enchanted creature gets +X/+X until end of turn.
When enchanted creature dies, return it to the battlefield under your control.

Enchant creature
When Rotten Retinue enters, return target creature card from your graveyard to your hand.
Enchanted creature gets +2/+2 and has deathtouch.