Reclusive Copse enters tapped. {T}: Add {B} or {G}. {1}{B}{G}: Until end of turn, Reclusive Copse becomes an Insect creature with deathtouch in addition to its other types. Scavenge {B}{G}
When Recognification Process enters and at the beginning of your upkeep, create a token that's a copy of target artifact you control, then sacrifice an artifact.
“And I look upon the world again and again and again, hoping to find something.” —Alida
Flash Creatures your opponents control have base power and toughness 1/1. Fleeting {1}{W}{W}(You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)
Return target nonland permanent to its owner's hand. Then that player discards a card.
“The sights are terrible, but you must not look away. See them not as parts of a horror play or a tragedy, but as what they are: the truth.” —Salome, to Paul
When Recollection Revelation enters, rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.) {1}{W}, Sacrifice Recollection Revelation: Return another target artifact or enchantment card from your graveyard to your hand.
Target spell's controller manifests it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
When Recon Drone enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle. Then if you did, put a card from your hand on the bottom of your library.
Most of Skalor's wildlife has metal as part of its biology. Some creatures found the extra defense lacking, and used the new support to grow bigger than ever before.
When Reconnaissance Expert enters, mill four cards. When Reconnaissance Expert dies, return target noncreature permanent card from your graveyard to your hand.
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.)
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.)
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.)