msem-instigator

When Reconnaissance Expert enters, mill four cards.
When Reconnaissance Expert dies, return target noncreature permanent card from your graveyard to your hand.

Choose one —
• Counter target spell unless its controller pays {2}.
• Draw a card.

Destroy target noncreature permanent. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Flash
Prowess
When Reconstructed Adept enters, target instant or sorcery card in your graveyard gains agonize until end of turn. (You may cast it by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile that card.)

Return target creature card from your graveyard to your hand.
Draw a card.

Choose one or both —
• Destroy target enchantment.
• Return target artifact card from your graveyard to your hand.

Flying, lifelink
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Recreator of Myths attacks, you may cast target instant or sorcery spell from your graveyard. If you do, exile that card instead of putting it into your graveyard as it resolves.

Deception {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever a Pirate or Rogue you control deals combat damage to a player, rediscover a Pirate or Rogue card. (Look at the top card of your library. You may reveal it and put it into your hand if it's a Pirate or Rogue. Otherwise, put it back or into your graveyard.)

When Recruits of the Demeter enters, draw a card if you control another Pirate.

Whenever Recurring Abomination deals combat damage to an opponent, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.
{4}{B}{B}: Return Recurring Abomination from your graveyard to the battlefield tapped.

When Recursion Runner enters, create a Function token with “If this spell isn't a copy, copy it. You may choose new targets for the copy.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

When Red Flower Assassin enters, destroy target creature.
Revive {5}{B} ({5}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Trample, haste
When Red Pelt Hart deals combat damage to a player, return it to its owner's hand.
At the beginning of your end step, sacrifice Red Pelt Hart.

When Red-Crowned Admiral 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 flying.

Other creatures you control get +0/+1.
{T}: Add {G}.

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

First strike
Redeye Commando's power is equal to twice the number of artifacts you control.
Redeye Commando attacks each turn if able.
Whenever Redeye Commando attacks, if its power is 6 or greater, it gains menace and trample until end of turn.

Redgill Corsair gets +1/+0 as long as you control an artifact.
When Redgill Corsair dies, create a Treasure token.

Redleather Armorer gets +1/+1 as long as it's your turn.

Counter target spell unless its controller pays its mana cost. (For example, if a spell costs {1}{U}{U}, its controller must pay {1}{U}{U}.)

First strike
Whenever an opponent casts a noncreature spell, you gain 2 life.

Counter target spell.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Target player sacrifices a creature. Then you gain 3 life if that player doesn't control any creatures.

Whenever you draw a card, put a hatch counter on Reefcrown Egg.
{T}, Sacrifice Reefcrown Egg: You may put a creature card with mana value less than or equal to the number of hatch counters on Reefcrown Egg from your hand onto the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Counter target creature spell. If this spell was kicked, create a 1/1 colorless Thopter artifact creature token with flying.