msem-instigator

When Rigid Conformist enters, for each {W} spent to cast it, create a 1/1 white Human creature token.
Each creature you control gets +2/+2 if you control another creature with the same name as that creature.

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.

Rilken Forcefield Keeper gets +1/+1 for each enchantment you control.
Sacrifice Rilken Forcefield Keeper: Exile target permanent you control. Return that card to the battlefield under your control at the beginning of the next end step.

Whenever another creature you control enters, put a +1/+1 counter on it.
Whenever Rilken Preserver attacks, you may exile target nonland permanent you control, then return it to the battlefield under your control.

{T}: Exile target creature you control.
{2}, {T}: Target creature you control becomes a copy of a card exiled with Ring of Remembrance until end of turn.
{4}, {T}, Sacrifice Ring of Remembrance: Each creature becomes a copy of a card exiled with Ring of Remembrance until end of turn.

This spell can't be countered.
Haste
Whenever a creature dealt damage by Ripper of the Fang Den this turn dies, put X +1/+1 counters on Ripper, where X is his power.

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.

Submerge all creature cards in graveyards. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

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.

Flying, deathtouch
Whenever Risen Raven deals combat damage to a player, draw a card.

You gain 4 life. Surveil 2.
Whenever you cast a spell, you may pay {W} and exile Rising Faith from your graveyard. If you do, that spell gains lifelink. (If it becomes a permanent, it keeps lifelink indefinitely.)

You can't draw cards.
{2}{R}: Exile the top card of your library. You may play it this turn.

{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.

At the beginning of your upkeep, if an opponent has more life than you, create a 4/4 red Elemental creature token with haste and “Creatures blocking this creature have winnow.” (Damage dealt to a creature with winnow causes its controller to lose that much life.)

As an additional cost to cast this spell, sacrifice a noncreature permanent.
Search your library for a creature card with mana value equal to 1 plus the sacrificed permanent's mana value, put it onto the battlefield, then shuffle.

Destroy all creatures with mana value 3 or less.

{T}, Pay 1 life: Add {W}.
{6}{W}{W}{W}, Exile Rius, Temple of the Grandfather from your hand: Target player gains 20 life.

As long as your deck contains only blue and colorless cards, your minimum deck size is reduced by eight.

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.

Creatures you control get +2/+0 and gain menace until end of turn. (They can't be blocked except by two or more creatures.)

Whenever Roaring Illusion attacks alone, for each other creature you control, create a token that's a copy of that creature and that's tapped and attacking. Exile those tokens at the beginning of the next end step.

Search your library for up to two basic land cards and put them onto the battlefield tapped, then shuffle.
Fuse (You may cast one or both halves of this card from your hand.)

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}.