msem-instigator

Bleed {2}{R}{R} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
When Restless Hedonist enters, discard your hand, then draw three cards.

Whenever an opponent casts a spell during your turn, create a token that's a copy of Resurging Rhino.

When Rethia Cultivator enters, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

Flying
When Reticent Possessor enters, you may attach target Aura you control to target permanent or player it could enchant.

Lifelink
{W}{B}, {T}, Discard a card: Look at the top three cards of your library. You may reveal an enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
When you have no cards in hand, exile Revela, then return her to the battlefield transformed under her owner's control.

When Reverence Seeker dies, you may return another target Knight card from your graveyard to your hand.

Menace
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.)

Each instant and sorcery card in your hand has orchestrate. Its orchestrate cost is equal to its mana cost reduced by {2}. (You may exile those cards from your hand anytime you could cast a sorcery for their orchestrate cost. When you next resolve a spell, you may cast it from exile without paying its mana cost.)
When you cast your third spell this turn, exile Reytali, then return her to the battlefield transformed.

Prowess

At the beginning of your upkeep, you lose 1 life and choose one —
• Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
• You may sacrifice an artifact. If you do, draw a card.

Wanderlust — When Riftbreaker Mage dies, if you control four or more differently named lands, Riftbreaker Mage deals damage equal to its power to each opponent.

Double strike
Whenever an opponent casts a noncreature spell, Riko, the Paragon deals 2 damage to that player.
Whenever a creature you control becomes blocked, untap it.

Flying
When Rimecraft Owl enters, you may put an Aura card with mana value 3 or less from your hand or graveyard onto the battlefield attached to Rimecraft Owl or target creature an opponent controls that Aura could enchant.

Saga spells you cast cost {1} less to cast.

Flash
When Rippling Water Arcanist enters, copy target instant or sorcery spell you control, then return it to its owner's hand. You may choose new targets for the copy.

Artifact and enchantment spells you cast cost {1} less to cast.
Whenever Risti Salvager attacks, rediscover an artifact or enchantment card. (Look at the top card of your library. You may reveal it and put it into your hand if it's an artifact or enchantment card. Otherwise, put it back or into your graveyard.)

Reach
When Risti Watchkeeper enters, rediscover a creature card. (Look at the top card of your library. You may reveal it and put it into your hand if it's a creature card. Otherwise, put it back or into your graveyard.)

{T}: Add {C}.
{1}: Risti Workshop becomes a creature in addition to its other types until end of turn.
When Risti Workshop deals combat damage to an opponent, you may sacrifice it. If you do, search your library for a basic land card, put it onto the battlefield, then shuffle.

{7}{U}: Tap up to three target nonland permanents. This ability costs {2} less to activate if you control a legendary creature.

When Rixia, Rift Shunted enters, target creature can't be blocked this turn.
Whenever a creature you control deals combat damage to an opponent, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Flying
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

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

When Rocket Admin enters, you may pay 3 life. When you do, gain control of target creature or planeswalker with mana value 3 or less until its owner pays {3}.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its costs.)
{1}{R}, Discard a red card: Roggar deals 2 damage to any target. This damage can't be prevented.
{2}{R}, Exile a red card from your graveyard: Create two tapped 1/1 red Elemental creature tokens.

Flash
Flying
Romantic Wisp can block only creatures with flying.