msem-instigator

At the beginning of your upkeep, Reality Collapse deals 1 damage to each opponent.
{2}{R}: Until end of turn, whenever an opponent is dealt noncombat damage, Reality Collapse deals that much damage to target creature that player controls.

{T}: Add {C}.
{T}, Reappropriate: Add one mana of any color. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

{T}: Add {C}.
{1}, {T}: Add one mana of any color. This ability costs {1} less to activate if there are three or more colors among cards in your graveyard.

You may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of lands you control.

Reveal the top X cards of your library, where X is the number of lands you control. Put any number of permanent cards revealed this way onto the battlefield and the rest on the bottom of your library in a random order.

Reach
Whenever you cast a spell with mana value 5 or greater, Reaper Squad deals 3 damage to target player or planeswalker.

You may have Reaping Willow assign its combat damage as though it weren't blocked.
{2}{G}: Reaping Willow gains indestructible until end of turn.

Reason Rots, Rage Remains deals X damage to any target.
Reconstruct {X}{R}{R} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

Gain control of target creature until end of turn. Untap that creature. It gains haste and defiance until end of turn. (Whenever that creature takes damage, if it survives and wasn't defiant, put a +1/+1 counter on it and it becomes defiant.)

As Reborn Altar enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}, {W}, or {B}.

Exile the top card of your library and up to one target permanent card from your graveyard. You may play cards exiled this way until the end of your next turn.
You may play an additional land this turn.

Exile target instant or sorcery spell you control. Until end of turn, you may cast that card from exile without paying its mana cost. When you do, copy it. You may choose new targets for the copy.

Tap up to three target lands. They don't untap during their controller's next untap step.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

{T}, Sacrifice a land: Untap up to three target lands.

Haste
Whenever Reckless Dunerider attacks, if it's enchanted or equipped, you may draw a card. If you do, discard a card.

Trample
When Reckless Exemplar attacks, if its power is greater than its base power, target creature an opponent controls can't block this turn.

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
When Reckless Guardian dies, create X 1/1 colorless Servo artifact creature tokens, where X is Reckless Guardian's power.

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

{T}: Target creature gains haste until end of turn.
{1}{R}, {T}, Sacrifice a Human: Create a token that's a copy of the sacrificed creature, except it's a 3/2 colorless Horror. It gains haste until end of turn. Activate only as a sorcery.

Haste
Whenever Reckless Pyremage becomes tapped, it deals 1 damage to each creature and each player.

Reckless Rage deals 4 damage to target creature you don't control and 2 damage to target creature you control.

Target creature gets +3/+0 and gains haste and winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Trial 6 (As you cast this spell, an opponent of your choice may pay 6 life. If they don't, they fail the trial.)
Flying
When Reckoner of Man enters, if the trial was failed, it deals 3 damage to each creature you don't control.

Return up to three target land cards from your graveyard to your hand.
Coalesce {6}{G} (You may cast this from your graveyard for {6}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Put target artifact, enchantment, or card in a graveyard on the bottom of its owner's library.