msem-instigator

Target creature gets +3/+0 and gains first strike until end of turn.

Exile the top two cards of your library. Until the end of your next turn, you may play those cards. (If you cast a spell this way, you still pay its costs. You can play a land this way only if you have an available land play remaining.)

As an additional cost to cast this spell, put a card from your hand on the bottom of your library.
Draw two cards.

Gain control of target creature until end of turn. Untap that creature. Then create two 1/1 red Satyr creature tokens with “This creature can't block.” Creatures you control gain haste until end of turn.

Rushing Waters enters tapped.
{T}: Add {U} or {R}.
When Rushing Waters enters, you may put a loyalty counter on a planeswalker you control.

Flying
When Rushwater Hunter enters, you may return target creature to its owner's hand.

Improve {1}{U} ({1}{U}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of your end step, if one or more embattled creatures you controlled dealt damage to a player, you may draw a card. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Russet Denmother enters, choose one —
• Destroy target enchantment.
• Create a 2/1 red and white Fox creature token.

Rustshell Crustacean gets +1/+1 for each artifact you control.
Whenever Rustshell Crustacean attacks, choose one —
• Search your library for an Equipment card, reveal it, and put it into your hand, then shuffle.
• Create a Treasure token.

Whenever Rustshell Mantis is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Deathtouch
Whenever Ruststep Centipede deals combat damage to a player, you may destroy target artifact or enchantment that player controls.

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Target creature gains trample until end of turn. The next time a source of your choice would deal damage to that creature, prevent that damage. If damage is prevented this way, that creature gets +X/+0 until end of turn, where X is the amount of damage prevented this way.

Whenever another creature with power 4 or greater you control attacks, Ruthless Brawler deals 1 damage to defending player.

When Ruthless Conscript dies, arm up to two target creatures you control. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Whenever you cast a spell that's red, green, white, or blue, each opponent loses 1 life and you gain 1 life.

{2}{R}: Ruthless Mastiff gets +3/+0 until end of turn.

{2}, Remove a counter from another permanent you control: Ruthless Monstrosity gets +2/+2 until end of turn.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Ruthless Predator can't be blocked by more than one creature.

{T}, Sacrifice a creature: Conjure a card named Data-Point into your hand. Activate only as a sorcery. (It's a sorcery that costs {2} with “Draw a card.”)

Whenever a Survivor you control dies, target creature you don't control gets -1/-1 until end of turn.

Whenever another creature you control dies, put a +1/+1 counter on Ruthless Weichafe and you lose 1 life.
Whenever Ruthless Weichafe attacks, if its power is 4 or greater, it gains lifelink until end of turn.

Haste
Whenever an embattled creature you control deals combat damage to a player, you may pay {2}{G}. If you do, create a token that's a copy of that creature, except the token isn't legendary if the creature is legendary. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Ryleth, Vengeful Shadow enters, create two 1/1 green Elf creature tokens.
Whenever you attack, you may pay {1}{B/G}. When you do, return target creature card with mana value less than or equal to the number of attacking creature tokens you control from your graveyard to the battlefield tapped and attacking.

S-19 Long Jacket has first strike as long as it's attacking.
S-19 Long Jacket has lifelink as long as it's blocking.