msem-instigator

Haste
Whenever Rapid Rodent attacks, it gets +1/+0 until end of turn for each other creature you control with flash and/or haste.

Untap target creature. It gets +2/+2 and gains reach until end of turn.
Monument {3}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

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

Ravaged Monument enters tapped.
{T}: Add {G}.
{2/G}{2/G}: Ravaged Monument becomes a 4/4 green Elemental creature until end of turn. It's still a land.

Equipped creature is a Flagbearer in addition to its other types.
While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.
Equip {5}

When Ravenous Abomination enters, choose one —
• Create two Treasure tokens.
• Put a +1/+1 counter on Ravenous Abomination.

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.

Ravenous Hydra enters with X +1/+1 counters on it.
Whenever Ravenous Hydra deals combat damage, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)

Double strike

As an additional cost to cast this spell, you may sacrifice a creature. If you do, this spell costs {3} less to cast.
Create two 3/3 white Construct enchantment creature tokens.

Once each turn, when a creature you control enters, you may draw a card if its power is greater than each other creature's power.

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Rawthlin Market Line enters tapped.
{T}: Add {G}.

{T}: Add {C}.
{2}, {T}: Target creature gains haste until end of turn.

Reveal the top five cards of your library. You may put a creature or Equipment card revealed this way into your hand. Then put the rest on the bottom of your library in any order.

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.)

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.