msem-instigator

{1}{G}, {T}, Discard a card: Another target creature you control gets +X/+X until end of turn, where X is 4 minus that creature's power.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Trample
When Rosenhulk enters, choose one —
• Create two 0/1 green Plant creature tokens with “{T}: Add {G}.”
• Destroy target artifact or enchantment.
• Rosenhulk fights target creature an opponent controls.

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

When Rotfeeder Slime dies, you gain 2 life for each creature card in your graveyard.

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.)

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.

Royster Hounds can't be blocked by creatures with power 2 or less.

This spell has flash as long as you control a creature with power 4 or greater.
Target creature you control deals damage equal to its power to target creature you don't control.

At the beginning of combat on your turn, Ruination's Hand gains flying until end of turn if a creature you control or a creature card in your graveyard has flying. The same is true for first strike, double strike, deathtouch, hexproof, haste, indestructible, lifelink, menace, reach, trample, and vigilance.

Trample
Whenever Ruinous Glutton deals combat damage to a player, destroy target artifact or enchantment that player controls.

Ruins Monitor can't be blocked by more than one creature.

Ruins Pack gets +2/+2 as long as you sacrificed a permanent this turn.

Ward {2}
{G}{G}{G}, {T}, Exile a creature card from your graveyard: Search your library for up to two creature cards that share a name with the exiled card, reveal them, put them into your hand, then shuffle.

Trample
Players can't activate abilities of nonbasic, noncreature permanents.

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.)

Target creature you control gets +1/+1 until end of turn. It deals damage equal to its power to target creature you don't control.
Madness {3}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

The first creature spell you cast each turn costs {2} less to cast.
At the beginning of your upkeep, return a creature you control to its owner's hand. If you do, you draw cards and gain life equal to its power.

Changeling (This card is every creature type.)
This creature enters with four -1/-1 counters on it.
Whenever another creature you control enters, if that creature has greater power or toughness than this creature, remove a -1/-1 counter from this creature.

Target creature gets +3/+3 until end of turn. If this spell was foretold, it gets +5/+5 until end of turn instead.
Foretell {1}{G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

You may spend mana as though it were mana of any color to cast spells with mana value 5 or greater or to activate abilities of permanents or permanent cards with mana value 5 or greater.
{T}: Add {C}.

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.)