msem-instigator

Flying
{U}: Ripclaw Drake gets +1/-1 until end of turn.

At the beginning of your end step, aetherize target permanent you control. (To aetherize, create a token that's a copy of it, then exile that token.)

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.

Return target permanent to its owner's hand.
Coalesce {7}{U} (You may cast this from your graveyard for {7}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Enchant creature you control
When Rise of Heroes enters or enchanted creature dies, search your library for a creature or planeswalker card with mana value 3 or less, reveal it, put it into your hand, then shuffle.
Enchanted creature gets +1/+1 for each creature and/or planeswalker you control.

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Madness {1}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Enchant creature
When Rising Tides enters, draw a card.
At the beginning of each upkeep, if enchanted creature is untapped, tap it.

Spells you cast that target Risti Operative cost {1} less to cast.
Abilities you activate that target Risti Operative cost {1} less to activate.

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.)

When Ritesinger Shaman dies, each player discards a card.

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

Flying
Whenever Rivha and at least two other creatures attack, exile all other attacking creatures you control. For each creature exiled this way, create a 3/3 white Angel creature token with flying that's tapped and attacking.

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.)

First strike
Whenever a creature dealt damage by Roadside Reaper this turn dies, you may discard a card. If you do, put a +1/+1 counter on Roadside Reaper and draw a card.

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}.

At the beginning of combat on each of your turns, you may sacrifice a land or exile a land card from your graveyard. If you do, create two 1/1 red Goblin creature tokens with haste. Exile those tokens at the beginning of the next end step.

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.

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.

Whenever you cast an instant or sorcery spell, reveal the top card of your library. If an instant or sorcery card is revealed this way, draw a card.

Whenever Rolling Homestead becomes a creature, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a creature you control attacks alone, add a quest counter.
1, 2 — Target creature can't block this turn.
3 — Gain control of target creature until end of turn. Tap it. It becomes attacking.
​

Pay 3 life: Put a +1/+1 counter on target creature.

For each nontoken enchantment you control, conjure a duplicate of it into your hand. Until the end of your next turn, you have no maximum hand size.
Exile Root Duplication.