msem-instigator

Target creature you control gets +2/+2 and gains lifelink until end of turn. It fights up to one target creature you don't control.

First strike, lifelink
Tribute 4 (As this creature enters, an opponent of your choice may put four +1/+1 counters on it.)
When Righteous Priestess enters, if tribute wasn't paid, the chosen player can't cast creature spells during their next two turns.

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.

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.

Flying
Whenever Rimebreath Tyrant attacks, you may discard a card. When you do, tap target creature. It doesn't untap during its controller's next untap step.

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.

This spell costs {1} less to cast for each instant and/or sorcery card in your graveyard.
Once each turn, when you cast an instant or sorcery spell, you may create a 4/4 white Angel Cleric creature token with flying and vigilance.

First strike
Engage (This creature must be blocked each combat if able.)

Foretell {2}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Attacking creatures get +2/+0 until end of turn. If this spell was foretold, those creatures also gain trample until end of turn.

Destroy target creature. Its controller loses 1 life.

Flying
{U}: Ripclaw Drake gets +1/-1 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.

Concord — When Riptide Mystic enters, if there are four or more card types among permanents you control, you may return target nonland permanent to its owner's hand.

When Rise from Death enters, exile all cards from your library. When Rise from Death is no longer on the battlefield, shuffle your graveyard into your library.
If you would draw a card, instead return a card from your graveyard to your hand. If you can't, you lose the game.
If a card would be put into your graveyard from anywhere, exile it instead.

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.)

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

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.

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

Trample
Risti Assault Squadron can't attack unless all other creatures you control also attack. (It can attack if it's the only creature you control.)