msem-instigator

When Raikai Seafarer enters, you may search your library for up to three cards named Raikai Seafarer, reveal them, put them into your hand, then shuffle.

{T}: Look at the top card of your library. If its mana value is equal to the number of lands you control, you may reveal it and draw a card.
{1}, Return a land you control to its owner's hand: Scry 1.

Trample
Art of war — At the beginning of your end step, if Raiun Bay Admiral dealt damage to an opponent this turn, put a +1/+1 counter on each other creature you control.

Rakkiri Archer gets +0/+1 and has reach as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Rakkiri Aspirant enters, if you control an embattled creature, exile the top card of your library. Until end of turn, you may play that card. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Haste
Whenever a player casts a spell, Rakkiri Dissident deals 1 damage to that player.

Rakkiri Initiate gets +0/+2 as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Rakkiri Piker has double strike as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

When Ralezza, Weaver of Okthuros enters, you may put target Aura card that could enchant it from a graveyard onto the battlefield attached to Ralezza.
{1}{W}, Sacrifice an Aura: Ralezza gains indestructible until end of turn.

Whenever you cast a spell that doesn't share a color with Raloran Adept, you may switch target creature's power and toughness until end of turn.

Each Merfolk and Wizard you control has “Whenever this creature attacks, abound.” (To abound, you may cast a spell that costs less than that creature from your hand without paying its mana cost.)

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.

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.

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.

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

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.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Infiltrate (Whenever one or more attacking creatures you control aren't blocked, this creature gets +1/+1 until end of turn.)

Menace
When Rattled Bones dies, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Reach, deathtouch
Whenever you cast a spell from your graveyard, you may have Raven-Cursed Dominik fight target creature.

Whenever one or more other creatures you control deal combat damage to an opponent, choose one —
• That player discards a card at random.
• That player sacrifices a creature with toughness 4 or less.

First strike, trample
Whenever a creature dealt combat damage by Ravenous Forsaken this turn dies, put a +1/+1 counter on Ravenous Forsaken.
{2}{R}: Ravenous Forsaken gets +3/+0 until end of turn.

Tap X untapped Shamans you control: Ravik, Still-Smoke Seer deals X damage to any target and you gain X life.

Whenever a Survivor you control enters, you may draw a card. If you do, discard a card.

Death knell — You may sacrifice a nontoken creature. If you do, create a 3/3 black Spirit creature token. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
Creatures you control dying causes their death knell to trigger. (In addition to the normal death knell trigger.)