msem-instigator

Target creature gets -4/-4 until end of turn. When it dies this turn, create two 1/1 black Worm creature tokens.

At the beginning of your upkeep, if an opponent has more life than you, create a 4/4 red Elemental creature token with haste and “Creatures blocking this creature have winnow.” (Damage dealt to a creature with winnow causes its controller to lose that much life.)

Bloodprice {B} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Destroy target creature.

Menace
Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, each opponent discards a card.

Creatures you control get +2/+0 and gain menace until end of turn. (They can't be blocked except by two or more creatures.)

Discard Robocamel: Create a Food token. Activate only as a sorcery. (It's an artifact with “{2}, {T}, Sacrifice this artifact: You gain 3 life.”)

Trample
Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Rockpounding Saurian enters, if tribute wasn't paid, you may destroy up to one target artifact, up to one target land and up to one target Fortress.

Flying
When Rooftop Robber enters, another target Pirate or Rogue you control gets +2/+0 and can't be blocked this turn.

When Rootbound Awakener enters, create a green Aura enchantment token named Vivification attached to target creature or land. The token has enchant creature or land and “Enchanted permanent is a creature with base power and toughness 5/5 in addition to its other types.”

{6}: Create a 1/1 black Worm creature token.

Create a 1/1 green Saproling creature token for each nonland permanent card in your graveyard.

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.

[+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}.

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 creature you control enters, you may have it get +1/+1 until end of turn. If you do, it fights target creature. (Each deals damage equal to its power to the other.)

Runewart Hog has hexproof as long as it has a +1/+1 counter on it.

Whenever Rustshell Mantis is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Flying
Legendary spells you cast cost {1} less to cast.
{W}{U}{B}{R}{G}: Search your library or graveyard for a legendary card, reveal that card, and put it into your hand. If you searched your library this way, shuffle.

S-19 Long Jacket has first strike as long as it's attacking.
S-19 Long Jacket has lifelink as long as it's blocking.

Enchant creature
Enchanted creature gets +3/+3 and has flying and vigilance.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

[+1]: Draw two cards, then put a card from your hand on the bottom of your library unless you've spent {W}{U}{B}{R}{G} on spells this turn.
[–2]: Add {W}{U}{B}{R}{G}.
[–6]: For each card type, you may return a card of that type from your graveyard to your hand.

When Saffrisa's Darkcaster enters, look at the top four cards of your library. You may substantiate a card from among them. Put the rest into your graveyard. (To substantiate a card, put it onto the battlefield face down as a 2/2 creature. You may turn it face up and cast it at any time for its mana cost if it isn't a creature.)

Flying
When Sage of Dilemmas enters, return up to one target enchantment to its owner's hand.