msem-instigator

{2}{G}: Rotted Kalak gains indestructible until end of turn.
Revive {3}{B} ({3}{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.)

Enchant creature
{X}{B}: Enchanted creature gets +X/+X until end of turn.
When enchanted creature dies, return it to the battlefield under your control.

Enchant creature
When Rotten Retinue enters, return target creature card from your graveyard to your hand.
Enchanted creature gets +2/+2 and has deathtouch.

Deathtouch

{T}, Pay 1 life: Add {C}.
Unveil {3}{B}{G} ({3}{B}{G}: Transform this. Unveil only as a sorcery.)

When Rotting Greatwurm dies, put three +1/+1 counters on target creature you control.
Fleeting {2}{G} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

When Rotting Sunseeker dies, return target creature card with power 2 or less from your graveyard to your hand.

{T}: Add {B} or {G}. You lose 1 life.

{1}{B}, Exile a creature or land card from your graveyard: Return Rotwood Whisper from your graveyard to the battlefield tapped.

Destroy target land. Create a 2/2 black Zombie creature token.

When Rousing Battlehound enters, other creatures you control get +1/+1 until end of turn. Other Hounds you control gain first strike until end of turn.

Creatures you control get +1/+1 until end of turn. If you control a Rebel, draw a card.

Rouse 4. (Distribute four +1/+1 counters among permanents you control. If they aren't creatures, tap them and they become 0/0 creatures in addition to their other types.)

Once each turn, when Rova, the Fleshweaver enters or you attack with one or more Horrors, you may put a +1/+1 counter on each creature you control. Then if Rova isn't a token, untap each land you control. Until your next turn, you may cast permanent spells as though they had flash.
{2}{G}{G}, Discard Rova: Create a token that's a copy of Rova, the Fleshweaver, except it's 4/4 and isn't legendary. Activate only as a sorcery.

When Roving Chaplains enters, create two 1/1 white Spirit creature tokens with flying.
{W}, Tap another untapped creature you control: Tap target nonland permanent an opponent controls.

Whenever Roving Dreadnought attacks, you may salvage a card that was put into your graveyard this turn. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

Gain control of up to two target creatures until end of turn. Untap them. They gain haste until end of turn.
Menagerie — If there are five or more creature types among creatures you control, untap all creatures you control. Until end of turn, they gain “{T}: This creature fights another target creature.”

[+1]: Tap target permanent. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
[0]: Put target artifact, instant, or sorcery card from your graveyard on top of your library. If you have an insight counter, you may return that card to your hand instead.
[0]: You get an insight counter.
[–1]: Target creature can't be blocked this turn. Until end of turn, whenever that creature deals damage to an opponent, you draw a card.

Each Rogue you control can't be blocked by creatures with greater power than it.
Whenever a Rogue deals combat damage to a player, gain control of target nonland permanent that player controls unless that player pays {1}.

Enchant creature
Enchanted creature gets -3/-3.

Vigilance
When Roya Ritualist enters or whenever you cast a spell, if {G}{U} was spent to cast it, draw a card, then you may put a land card from your hand onto the battlefield tapped. Put a +1/+1 counter on Roya Ritualist.

Whenever a permanent you control leaves the battlefield, put a +1/+1 counter on Royal Doctor.
When Royal Doctor leaves the battlefield, you gain life equal to its power.

Ward {2}
Foresight — Whenever you draw your second card each turn, Royal Falconer gains flying until end of turn.

First strike
Prevent all noncombat damage that would be dealt to Royal Knight.