msem-instigator

Whenever Ram Wrangler attacks, until end of turn, gain control of target creature defending player controls with power less than or equal to the number of creatures in Ram Wrangler's pack. Tap it. It's attacking defending player. (Two or more creatures you control with equal power are in a pack.)

At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a party counter on Rambunctious Afterparty. Then Rambunctious Afterparty deals damage equal to the number of party counters on it to each opponent.

Whenever Rambunctious Upstart attacks, up to one target creature gets -3/-1 until end of turn and up to one target creature gets +3/+1 until end of turn.

Rammanethi Hydroshaper gets +1/+1 as long as you control an Island.
{2}{U}: Target creature blocking or blocked by Rammanethi Hydroshaper gets -1/-0 until end of turn.

Reach (This creature can block creatures with flying.)
Whenever a land you control enters, Rammanethi Sandshaper deals 1 damage to target creature with flying.

Flash
Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)

Flash
Motivate 7 (When this creature enters, you may motivate target creature with less power than this by putting seven +1/+1 counters on it.)

When Rampaging Xiangshe enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Each creature you control with a +1/+1 counter on it has trample.

At the beginning of your upkeep, mill two cards.

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

({T}: Add {R} or {G}.)
Whenever Rampant Summit becomes tapped, you lose 1 life unless you control two or more basic lands.

Defender, reach
Bulwark — {X}, {T}: Rampart Ballista deals X damage to each opponent. X can't be greater than the number of creatures you control with toughness 4 or greater.

When Ramzi, Traveling Merchant enters, adjudicate land. (Create a white enchantment Aura token with enchant land and “Sacrifice this token: Untap enchanted land.” attached to target land.)
Whenever an Aura becomes attached to a land you control, create a 1/1 green Antelope creature token.

When this creature enters, for each kind of counter on target permanent, put another counter of that kind on it or remove one from it.

Equipped creature gets +2/+3 and has reach.
Equip Scout or Archer {1}
Equip {3}

Look at the top six cards of your library. Put up to one land card and up to two creature and/or planeswalker cards with total mana value 5 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Target creature you control gets +1/+1 and gains hexproof until end of turn.

Haste
Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Enchant opponent
When Ranidaphobia enters, create a 1/1 blue Frog creature token.
Creatures enchanted player controls can't block Frogs.

Sacrifice a creature: Rapacious Demon gets +1/+1 and gains flying until end of turn. Activate only as a sorcery.

Enchant creature you control
When Rapacious Instinct enters, enchanted creature deals damage equal to its power to target creature you don't control.
Enchanted creature gets +1/+0.

First strike
When Rapacious Rattler enters, choose one or two targets you don't control. It deals 2 damage to the first and 1 damage to the second.

Flying
When Rapacious Regent enters, you may sacrifice another creature or artifact. If you do, Rapacious Regent deals 3 damage to any target.

Choose a Function added to Rapid Recursion. Create a Function token with those effects. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)
Draw a card.